There is standard, and standard as previously Chrome only feature that Firefox felt pressured to implement and was then a posteriori made into a standard.

Because (Unpopular): I believe the standard should primarily cover how the overlapping functionality works, and refrain from limiting or prescribing the extent of functionality.

Comparing: If I build a HTTP API, I don’t have to support the DELETE verb for any endpoints. I can support ENCHANT if I want magic that other servers don’t have. But if I use GET, the endpoint handler should be idempotent. That’s the kind of standard I appreciate.

I don’t see any realistic win-win otherwise. Either you hold Chrome back from implementing new crap, or you force Safari to implement stuff they don’t want to. The efficient number of browser vendors seems to be small, so I think the standard body has just overplayed it’s hand.