[lxgr]

There’s nothing wrong at all with adding features as long as more than one browser/engine actually adopts them.

[cosmic_cheese]

There’s an argument to be made that a high pace of new feature additions effectively functions as a moat that ensures that new competitive web engines cannot be developed as a result of not being able to ever catch up.

[lxgr]

Exactly: The part after "as long as" is both critical and hard to ensure.