chesheer on Nostr: I think that one of the most important problems of "user portability" between modern ...

I think that one of the most important problems of "user portability" between modern *nixes is a problem of file systems, i.e. data storage in general.
As far I can tell, Linux and *BSDs have one common denominator in terms of file systems: ext2fs. This is a filesystem any Linux or BSD system can access (I won't count NTFS and FAT, let's be serious here).
Which means that, given big enough amount of data you have to keep, moving between OSes becomes quite a task.
ext2 is very old. ZFS will never be a common denominator (OpenBSD is not going to put "half of Solaris kernel", as they say, in their own kernel). HAMMER2 probably might be a thing supported by all major players, but we're not there yet.
But we are too concerned with putting Rust in kernel and introducing local AI into desktop OSes.