Which filesystem do you use that handles large disks and can be mounted by Linux, Windows, and Mac?
If you don't need to use it on Mac/Windows, use a FS like BTRFS with checksumming feature.
Don't use any FS that doesn't have checksum feature as silent bitrot is real.
Linux has FUSE read-only support for decrypting APFS. iOS can read/write encrypted APFS that is formatted on macOS.
Would be nice to have encrypted ZFS support on multiple platforms, including iOS and Android.
ext4 can't be natively mounted in Mac and Windows but you can install third party software and still mount it from the command line easily. And of course ext4 works fine with Linux natively.
I don't know if you can install the Mac OS or Windows OS on an ext4 drive and directly boot from it, however.