It's certainly not obsolete as in "you shouldn't use it anymore", but it certainly is as in "there is really no reason to continue using it". While moving to BtrFS may be premature for most people, not moving to ext4 is somewhat eccentric. Ext4 is more than good enough.
> More amusing than this just the fact that the filesystem is a bottleneck for a web browser...
It's certainly not obsolete as in "you shouldn't use it anymore", but it certainly is as in "there is really no reason to continue using it". While moving to BtrFS may be premature for most people, not moving to ext4 is somewhat eccentric. Ext4 is more than good enough.
> More amusing than this just the fact that the filesystem is a bottleneck for a web browser...
Indeed.