I know next to nothing about Ableton but aren't projects mostly a bunch of uncompressed audio or other large binary media files? Git doesn't really do well with that.
Vast majority of musicians use DAW, although some famously don't, e.g. Burial uses Sound Forge for his music.
Doesn't make much of a difference, as it still has audio recording, plus audio samples you can drag as loops or as drum machine sounds, and things like that, that are per project (not necessarily in the library).
Any vocals for example would be 32-bit float lossless tracks, usually multi-tracked too. And any variation of a track, whether midi/vst based or audio based, that you chose to render to a clip (a very standard workflow, saves cpu and allows you to do audio edits to that part), will also be backed by an audio file on disk. Same for every "frozen" track.
So it might be a DAW and not a purely audio editor, but it will still have lots of audio files it manages.
The fact that MIDI tracks with VSTs on them render on the fly doesn't change this.
Even those VST-backed sequencer tracks generate audio files that are consolidated into the project folder, when the clip is rendered to audio for creative manipulations (common workflow in Ableton), or when it's frozen (also common to save CPU).