Everywhere exFAT is supported now. Windows, Mac, Linux, FreeBSD would be fine.

Presumably Microsoft fear making it easy to swap OSes and access the same data.

"I can use Linux because if I get stuck I can just switch to Windows and still access my data" is a comfort that probably keeps people from even trying Linux (or other OSes)?

Why else would MS not support BTRFS/ZFS/Ext or whatever?

{I'm not saying that I think this works.}