@mario >was running it in QEMU
Yes, versions with some of the sabotage patched out may work better (I'm pretty sure macos will refuse to run in a VM unless the sabotage part is disabled).

>find obscurish FOSS like betterbird, schildichat and freetube within homebrew
Those are hardly obscure if I can find them in a search engine.

Freetube is licensed under the AGPLv3 (unclear of -only or -or-later), which makes it free software and not "open source".

>I would be able to migrate my setup to MacOS without anything missing really.
You would be missing freedom, which to me is the most important thing.