anecdote but last year I sunk three solid weekends into trying to make git-annex work to sync my files between devices, and was defeated. it is such a fucking incomprehensible buggy pain in the ass.
I settled on syncthing instead. it has given me few troubles.
If SyncThing works for your use case, I agree that you should choose it over git-annex. However, git-annex is also much more flexible than SyncThing.
For example, if you want to protect your music collection from accidental changes and are willing to use it manually from the command line, git-annex will work better. Or when I used it for my music, I had a branch for all my lossless files, and then a separate branch for curated and transcoded files that I used for syncing to devices with less disc space. (Perhaps not the most useful example, but the point is that there are a bunch of git-annex workflows that have no parallel in SyncThing or similar tools.)
>if you want to protect your music collection from accidental changes and are willing to use it manually from the command line, git-annex will work better.
that's what plain old backups are for, surely? if I screw something up I can just restore from backup.
and anyway this is just not something that has ever caused me a problem in the first place. how often do you even do something that has a chance of fucking up your music collection in particular?
I settled on syncthing instead. it has given me few troubles.