Ever heard of planned obsolescence? The hardware absolutely changes after sale, there have been cases of keyboard's failing (e.g. during the butterfly keyboards), backlight failures (happened to some MBP runs), cracked displays (keys pressing into them), anti-reflective coating peeling, hinge issues (in several models), display failures (discoloration, light leaks), issues with (dedicated) GPUs in intel era models, battery expansions, logic board failures (there was a program that had 2-3 rounds or replacements), touch strip failures, and many others.

And that's just pure hardware. Hardware/battery performance dropping by OS updates has been well known, and there were a few class actions lawsuit Apple lost or settled and fined.