I've had plenty of issues with old bundled GCC compilers which were fixed in later versions. I'm feeling this is a psychological thing, not necessarily software related. (Doesn't invalidate the feeling though)

It has to be a pain, everything depends on them (or rather, should, you still have holdouts like go fucking up things like NSS, holding back posix_spawn etc.).

In their defense the people working on glibc and gcc are pretty intelligent and spend a lot of time thinking about how everything they do affects their users, though they make mistakes like all humans (and LLMs I should say by now).