Service Workers, for example, are just a working draft and somehow not having the spec implemented is considered as lagging.
PWAs are fine for some uses. However I think it would be better for everybody if the vendors were extra cautions when creating and approving these standards as these APIs tend to crystallise and browsers end up supporting a lot of deprecated cruft. I was young when MS was doing the same thing with IE6 but I still remember the pain in the ass making anything remotely compatible was. And back then we were not talking about access to stuff like microphone or background activity.
Are they good proposals? How could they be improved? Do they meet the needs of the various interested parties, most especially end-users? Taken together, are they coherent, do they compose and complement each other, do they move toward a robust, comprehensive software framework?
Maybe it's happening, but I don't see these questions being asked a lot, much less addressed. Should we all just trust in Google? And expect Apple, MS, and other browser vendors to do so as well, not to mention implement Google's APIs as quickly as they come out?
No doubt, there is a lot of good work coming out of Google, but overall, I don't think the present system will be sustainable nor result in a good web.