Dropbox sync will work only on EXT4 (unencrypted only, Linux), NTFS (Windows), APFS and HFS+ (both Mac OS).
pCloud might be a good alternative to Dropbox. It’s hosted in Switzerland and cheaper.
Rclone is also an option, but more of a DIY as you’d need to provide the backend storage.
Most of us use the default file system for their distro, so many will be able to keep using Dropbox.
Nextcloud will be big in Japan, as NEC are gonna make routers with Nextcloud pre-installed. Nextcloud 14 to be released in September is going to feature video authentication for shared files and lots of other new features.
Play Windows Steam Games on Linux with Proton, a fork of the Wine project. This could be a game changer for desktop Linux adoption, especially as some games, GTA V for example, show better max fps on Proton than on Windows. Linux to the masses!