They don't "wear out". They fail catastrophically without warning. A MOSFET or IGBT will suddenly short due to poor design, bad QA/QC, and knock-off underspecc'd components. When that happens, the full brunt of the 240v mains supply runs through the shorted transistor and blows everything up. Been there, done that. Used the machine maybe like 6-7 times. Company up and vanished with no support. Seen it happen to countless others. Even just recently on Garage Journal someone said their new HF inverter welder blew up, and they couldn't get parts for it.
Gosh, it amazes me how often I have to repeat myself on this site. I was pointing out that we, as Americans, plow on average $1200 each year on fast food. Poor quality food, lacking nutritional value, that provides us 30 seconds of enjoyment and 12 hours later gets flushed down the toilet.
Yet the idea of spending a year or two of equivalent fast-food money on a quality tool that will last forever is utterly unacceptable.
Until you draw the short-straw with your cheap $300 unit, and it blows up.
Why bother buying quality anything with that logic? Who cares about buying a nice screwdriver, when you can buy a 10 pack of screwdrivers from HF? If you break one, what does it matter? Why bother with DeWalt and Milwaukee tools when a HF drill will make a hole in wood just fine? Why buy quality knives for your kitchen, when you can just buy cheap knives and sharpen them every other day? Why bother spending money on a good compressor, when you can buy 4 cheap ones for the same price? Who cares about buying a nice computer, when you could get a $150 chromebook to browse the web?
In fact, I think we should just petition all of the retailers of premium brands to close their doors to general consumers. After all, a hobbyist only needs cheap garbage **** from Temu, Amazon and Wish.