> If it’s bad for users (e.g. some new ad tracking)
Yes
> but if it’s not that, then refusing to ever adopt those standards (or to provide their own alternatives) is either foolish NIH syndrome on Apple’s part or it’s greed.
Note that Firefox's position is literally exactly the same as Apple's on these Chrome-only features: https://mozilla.github.io/standards-positions/
Firefox gets paid by Google. A lot. Maybe part of their agreement is to not implement some features because it would compete with Chrome. I don't really know, and I don't really care what Firefox does or doesn't do. I only care that Apple does not allow other browsers to use their own browser engines. Opera mobile also implements the APIs I need (on Android). Even MS Edge supports the APIs. Firefox can join Apple in being lame, I don't really care.