Perhaps you don't see these problems if you use Windows. I wanted to use it as the marginal cost was 0 (already had to have a Word license) but I couldn't rely on it.
I don't like Dropbox spraying shrapnel through my mac's UI even though I told it not to, so don't take this as a defense of DB -- it simply sucks less and does the baseline (save my files) better.
Which is also my justification for using a Mac (sucks the least of the options available to me).
But there is a huge gap between official linux support by Dropbox and a thrid-party app.
In my experience, Dropbox's syncing experience is generally superior than the others, especially when it comes to file stability. Its history and time machine feature (or folder rewind) is so great.
First of all, this was about 2-3 years ago.. not sure if things have changed.
(1) Onedrive "for business" was completely different than OneDrive personal. It still worked under some archaic office sharepoint or whatever thing to some degree.. so first when I tried to use it there was some terrible path/file limitation (lower than normal windows) and it didn't like some special symbols.
So let's ignore that nightmare above, maybe it's changed.
(2) Even with onedrive personal and the business version I used.. it COULD NOT manage a lot of files. I mean even 50k-100k files it would just stop working basically. It would just sit there stuck, never do anything etc.
On Dropbox we have well over a million files and it works fine. Some chunk of files change all the time and it still works.
tl;dr if you have a LOT of files.. Dropbox is the way to go- nothing else I have tried comes even close to it.