Id say it probably is.
For single user backing up, archiving, cloud access for binary files... yeh, sharepoint/onedrive probably IS better than git.

BUT, i say that with 0 experience of using either for that. I use git for text, and i havent had the "pleasure" of onedrive/sharepoint.
But i have a feeling that onedrive/sharepoint will have an edge over git as a cloud drive system. Even if its just from a tooling/integration standpoint