I've been using RPis and secondhand mini PCs for embedded systems development and testing professionally for the past few years. I've got 3-4 dead Pis already out of a dozen or so that we have, a mixture of Zeros and 4s, which isn't exactly impressive. Meanwhile the couple dozen mini PCs, despite their age and having been bought used, have had only one failure, a RAM module which was trivial to replace. The failed Pis went into the electronics recycle bin because that's all you can do with them when the develop issues.

Sorry, I stand by my opinion that Pis are hobbyist playthings. I'm sure they were reliable for you but you probably weren't trying to do anything serious with them either.