If we want to know who to blame for the current state of US manufacturing, maybe look in the mirror and this forum is the perfect place to "reflect", since we have our lifelong obsession with Sears.
For a hundred years we could have paid and endless number of US manufacturers a fair price for their products. But, instead we went to Sears, where we could get that manufacturer's exact same(or similar) product - with a different name, for less money. Hell, in later years, wait for a sale and pay even less. Everything, not just tools. Underpants, refrigerators, tires. Wasn't even just Sears, Sam Walton, Kmart. Everybody had to feed those demanding "bargains", always searching for the lowest price.
When a manufacture has to "discount", that hurts their bottom line, no matter their volume. 9th grade economics. Might be one good reason that nearly tool (and ever other product) by a US company we love is either out of business, importing their products, or has been gobbled up by yet another greedy, profit obsessed conglomerate.
Obviously we are not here typing on our US made computers, but will bash HF for all of our problems, which almost sounds like organized propaganda. (but then I watch a lot of historical documentaries.

)
It's a script. People have it in their heads, and for some reason they're happy enough to not really inspect it for truth. It's the shiny target.
[I got really carried away and somehow this became my morning research project - apologies for the length, but didn't want to throw it away when I realized how overboard it is... ]
The Sears/Craftsman thing many of us have (or had) evolved from convenience as much as anything - Sears was easy and everywhere, if only by catalog for some in some areas (I'm just barely old enough to remember the four-inch-thick Sears catalogs). They had legacy, recognition and accessibility. I doubt non-professionals before the turn of the century could name a single tool brand outside of Craftsman - why would they? On top of that, the world of DIY was pretty limited. Before the internet (and especially YouTube), the size and scope of the DIY universe was pretty limited - the "how" information was pretty hard to get, so you called somebody. And lots of tools were not only expensive but hard to justify if you couldn't get the information to do things yourself.
As the internet began to flip that script, Sears was already crumbling (A) because they weren't evolving and (B) because their exec team was eating it from the inside. Walmart, Target, Amazon and many others finished it off. Of course, HF has been growing during that time too, though I'd guess box stores like Lowe's and Home Depot outstripped HF's sales in the tool category until relatively recently. They're probably the biggest standalone tool retailer, but 2022 revenue was apparently $5B, Home Depot was
$157B. Lowe's was
$96B. Obviously those guys sell vastly more than tools, but saying HF has shuttered US tool makers in the face of that is pretty laughable.
Everything I just mentioned almost completely leaves out the MiUSA tool makers (at least the ones we all talk about). They were focused on the professional market (and mostly still are). But while they were doing the same old thing (for the most part), the world of DIY exploded and a lot more tools from all over the place became available, especially China. Of course, Craftsman has already put in the mainstream - I vaguely remember seeing 'Made in China' on a set of wrenches I was buying and thinking something along the lines of "Well, it's what they have, and I guess if it says Craftsman..."). MiUSA was still focused on the pro market. The problems with that are (A) it's not growing all that fast, especially with DIY (B) the DIY tools were eating away at the edges of the pro market and (C) all that competitive pressure was drastically changing price points. What I paid for that Craftsman set of wrenches was probably close to $100 in today's dollars, which buys some much-nicer wrenches these days.
Net: what killed a lot of MiUSA tool brands was doing things the same way in the face of a radically-shifting world. Malco not being able to sell enough $45 MiUSA vice grips to keep the factory open isn't HF's fault. They got plenty of free advertising when they entered the market and still couldn't make it work. That market doesn't really exist any more.
In a lot of ways Sears is far more to blame than HF. At worst, Harbor Freight walked through the door opened by Sears and now owns the house. That house is in far better shape than it was back then IMHO. HF was pretty **** overall 25 years ago, but these days has a lot of compelling options. But in terms of market, it's still a sliver based on what info I can find:

The US power-tools market (where HF is probably very small/weak, but pretty obviously an area of focus for them lately), appears to be roughly the same size - low-ish $20B a year. Let's call it $45B combined.
At $5B, HF isn't dominating anyone, other than guys like Northern Tool, and probably in profitability in the segment. They're very visible, but they're not "the problem".
And again - the single most devastating and landscape-changing retailer in the world is Walmart, and it's not close. While Amazon is also a major force in terms of revenue and business model, they haven't changed the face of small towns all over the country where nearly every drug store, retailer, grocery store, etc. in those towns is obliterated when the local Walmart opens. Amazon hasn't been as-directly responsible for all kinds of small-to-medium-sized domestic production of things ranging from clothes to furniture to hardware/tools and more being closed and moved offshore. (FWIW, I'm not saying Amazon is a shiny, benevolent entity, I'm just saying they've dug fewer graves than Walmart).
For the record, I do occasionally shop at Walmart, but I at least think about it. I'm sitting on a couch made about three hours away. I have a couple dozen pairs of shoes/boots made in the USA. Almost all of my suits/business clothes and dress shirts were made here. My kitchen and dining room tables/chairs were made here. The jeans I'll wear tomorrow were made 35 minutes from here from denim made about an hour in the other direction in a factory that was the last of its kind in North America, and now closed. For a DIYer, I have more MiUSA tools (SnapOn, SK, Matco) than I can justify, but I got them mainly as presents to myself. I try to buy small and local when I can. But I'm very fortunate financially and ultimately the world doesn't support that in the way it used to. (I'm not trying to say/insinuate I'm wealthy - we make more than most and we're relatively frugal, especially my wife. The newest cars in my household are over 10 years old and we've been living in the same house for over 20 years)
I can't say I love what's happened, but I save the vitriol for my mirror and wallet, and assign a fair share of blame for the companies actually responsible for it (see the Walmart story in my previous post). HF and Lowe's have done their own damage - given their size vs. HF (50X revenue combined) they're likely a much-bigger killer of MiUSA than Harbor Freight. And, of course, they're also the main reason local hardware stores mainly don't exist any more too, which I definitely miss. When I look at HF and see a US-owned company employing 25,000 Americans who make competitive money and get category-leading benefits while providing me a lot of good-to-excellent value, options and customer service, I'm grateful they exist.
/rant