Why is it that Obsidian works with Icloud but not with Google Drive and Other cloud solutions?

as said in the title, putting the vault on icloud works perfectly but with Google Drive and other cloud solution it always have problems, did anybody already have a proper response to this?

Sometimes it depends on how the watch/sync mechanism is implemented by each provider.
In all cases, you should make sure that whatever sync solution you use it is configured to keep the file local (not a link to them to be downloaded on demand)

I’m using Mega for syncing obsidian between multiple PCs and an android phone without any problems.

Have you tried it?