I agree with all that. The only nuance I'd add is some people wrench as much for a distraction/hobby as the cost savings (that woufld probably describe me - started as cost but now is as much a hobby as anything). For me, I have several F80's in various lengths that I got as gifts to myself when jobs popped up where they'd be usesful. I have a smattering of Snap On stuff - e.g. my 3/8" torque wrench (hard to find one that had a flex head, and it makes plugs on my old BMW a lot easier, so I grabbed one on Craigslist for a pretty decent price), and even my fuse test light:

I've had that for a long time - can't even recall where I got it.
Anyway, my point is I've managed to create some level of self-justification to have some SO stuff, but I can't see any DIY'er going full SO for the garage.