For me personally it was a matter of benchmarks. In the past I have seen higher performance numbers especially when dealing with directories that contain a very large number of files creating / deleting vs ext4. I've not tested since the 5.11 kernel time-frame however. But to your point it would be nice to see XFS have an option to grow inode limits dynamically like brtfs instead of having to manually adjust it. I've honestly never even tried out brtfs but it looks like I should.