OneDrive cannot handle tons of files. It just doesn't work. It ends up freezing, you have no idea what's going on. Can't speak to macOS related stuff.
We finally were able to migrate off of this.. but we had a VERY file hefty folder structure. Instead of databases we chose to keep things in individual files for various reasons. Needless to say this didn't scale well, and there were about 750k files on the structure. Most of this was archival, but we simply didn't have the time or care enough to reduce the number of files.. we just wanted to be able to sync this to cloud data as is. Many files were super small, so never an absolute size thing just a LOT of files. And a chunk would keep changing throughout the day.
Dropbox was able to handle this for years- never an issue. Yeah it was fairly CPU intensive, but it worked very well.
I tried OneDrive on this.. what a nightmare. I tried owncloud, bittorrent sync, some others I can't even recall. Granted this has been about 3-4 years since I really tried some other ones with lots of files, but I was so annoyed every time I did.