To be fair, Mozilla-affiliated developers have accomplished some serious cleanup in recent years. New & redesigned features are fake tabs with special permissions instead of that unholy intertwining of web standards and local UI in C++. Storage is almost-proper sqlite3. Dynamic linking against system libraries old&new just works(tm). Even the vendored Rust packages more or less build fine, now even across multiple compiler versions. Plus, AMDs new-ish CPUs with ginormous L3 brought recompile (and thus, bisect) times to almost reasonable levels, so that is not as pressing of an issue any more. I would guesstimate only 25 years left at the current speed till Firefox can be considered maintainable again.

So will the mess suddenly disappear?