As an ex-Gentoo user, the pain in a was always bundled Vs shared libraries.
Shared libraries breaking ABI could mean recompiling half your operating system
On the other hand, bundled libraries meant insanely long build times and a sense of impurity/uncleanliness
Unfortunately, it looks like projects like ABI tracker are long dead:
Current Gentoo user here. This hasn't been a real issue for me in years.