Honestly, with all of the kvetching on these forums about frames breaking, you would think that it’s a common experience. But I don’t think so. I personally know only one rider who has experienced this, and it was on a relatively new aluminum frame that obviously was not manufactured properly… And the crack developed slowly, gave plenty of warning, there was no catastrophic failure resulting in a crash. He just returned the bike and the manufacturer provided a new frame.
By the same token, I ran a bike rental program that included about 50 relatively low priced bikes with aluminum frames. Given the bikes’ MSRP, I would guess that each frame was manufactured at a cost well under $50. And the people to whom we rented them (for nine months at a time - a school year), beat the hell out of them. Never saw a single problem with any of the frames in six years.