I certainly peacock every time the new latest greatest [thing] is added to the spec, and am certainly not shy about using those features. There is a handful of misses, but it feels a little dishonest to point the finger squarely at Google when HN in particular lights up like a Christmas tree with every new feature.
Want me to link to our discussion(s) about the new browser DateTime library - Temporal? Or what about Streams, Pattern Matching, Subgrid, Container Queries, color-mix, et al. We ask for this stuff, and we're thrilled when it arrives. Seems hypocritical to then turn around and complain that they're making the browsers "too complicated."
Well, HN isn't really of a unified opinion on the matter - you'll find as many people complaining about browser complexity as people who love these features. The thing is, only one choice between having them or not would make it harder to create new browsers.
Blink and v8 are open source. You don't even need to implement the spec yourself. New browsers can piggy back off open source (which is what Chrome, Firefox, Edge, etc also did) to help making a browser easier.
And who made the specs so stupidly complex in the first place?
Back in early 2000s you could visit pretty much every site using a KHTML-based browser and that was written by a handful of KDE devs.