Two that I hit on my corporate machine:
- struggles with too many files. Last I looked, official Microsoft documentation says to not exceed 100k files. Yet, $WORK wants to dump basically every file I touch inside there. My Teams folder alone is ~20k files.
- has a max file path limit which is less than the allowable on NTFS. I use some software with a heavily nested folder structure which One Drive cannot accommodate. A valid Windows file path cannot be backed up by their promoted solution.