There’s a difference between source available and open source. For example, actually being allowed to distribute modified versions is pretty damn important:

Restrictions

• No Distribution of Modified Versions: You may not distribute modified versions of the software, whether in source or binary form.
• No Forking: You may not create, maintain, or distribute a forked version of the software.
• Official Distribution: Only the maintainers of the official repository are allowed to distribute the software and its modifications.

https://en.m.wikipedia.org/wiki/Contributor_License_Agreement

I mean it worked for long enough 🤷‍♂️

Sure, but it’s nicer that I would stop using my phone because it’s not worth repairing anymore rather than because it’s not supported.

You overestimate most people. “KDE is bad. Admittedly last time I tried it was 15 years ago” is a real quote that I read.