Maybe I have just had back luck but syncing my files across all of my devices has always burned me at some point. No matter what software I have used I have overwritten something by accident or I try and delete something and it doesnt get deleted on all device. Or get a bunch of conflicting files and now i need to figure out what file I want etc...
I do use some syncing but it is mostly between only two devices. Often times it is only a 1 way sync. For example photos on my phone get synced to my NAS automatically.
For me keeping all of my files in one place is the way to go. I just have everything on a NAS. (TrueNAS) All of my devices connect to that and i just edit them directly over the network.
I have a VPN for remote access.
It is the title of a article not a question OP is asking.