This is what I thought too, but in my case it turned out my drive was busted and btrfs detected an error and went read only… which was super annoying and my initial reaction was “ugh, piece of shit filesystem!” But ultimately I’m grateful it noticed something was wrong with the drive. If I was just using ext4 I just would have had silent data corruption. In that sense other filesystems do silently do their jobs… but they also potentially fail silently which is a little scary. Checksums are nice.