Yeah, more than anything, up until recently the WebKit team primarily worked on things that Apple cares about, which is why for example it’s generally been more battery friendly than Gecko or Blink — Apple sells an absurd number of battery powered mobile devices, so they’ve got a powerful motivator to pay more mind to efficiency than most. Similarly, poor color space handling reflects badly on their devices’ displays and makes it more difficult to seamlessly blend WebViews in alongside native components.

Google and Mozilla by contrast don’t need to care as much about these things since they’re not going to take as much heat for poor battery life or color handling; on the platforms that most of their users are on, these are both the rule and not the exception so users don’t really protest.

Instead what Google cares the most about is asserting control over the web as a platform, which is directly reflected by the features they’ve prioritized.