Solo developer writes a library in C without ABI-stability-enabling practices and positions it as a desktop Linux system library. Linux distros, including Big Companies, ship it as such. The Solo developer hands the library over to Solo maintainer. Non-distro BigCo imports a copy of the library in their product, finds a security bug, and contributes a patch that fixes the security bug but breaks ABI compat.

Who should Social Media Takes hold responsible for an ABI-compatibility-preserving fix?

libxml2's sole maintainer Nick Wellnhofer steps down, meaning libxml2 is now no longer maintained.

https://discourse.gnome.org/t/stepping-down-as-libxml2-maintainer/31398

It's hard to estimate just how many companies depend on this software and critical security updates to the library, so I'm certain many will quickly step up and offer sponsorship to ensure a fundamental dependency doesn't just deteriorate without proper support.

Any day now.