Looking at the holistic picture (as anyone implementing an entire browser must), it's probably a stretch to say they're "designed" at all – web standards are a patchwork of almost archaeological layers built up over several decades. Even many deprecated bits must still be implemented to support the millions of websites users will want to visit. Backwards compatibility is hard :-/
This has never been true. We wouldn't have JavaScript if Netscape didn't go off and do their own thing. Netscape and Microsoft were locked in a fierce embrace-and-extend battle for the web. XMLHttpRequest wasn't even a standard when Gmail came out in 2004, and wasn't a standard until at least 2006.
Web standards merely describe the current world of web browsers and attempt to retroactively take credit for it.
>Web standards merely describe the current world of web browsers and attempt to retroactively take credit for it.
I'm not sure I understand what you mean here by "take credit" but, that aside, are you suggesting that it would have been easier for Netscape and Microsoft to cooperate (or for gmail to support both) without some standards?
Back in the day yes. Modern web standards upgrades are designed (a) because Google wants them, (b) for regulatory capture -- making it too difficult for a browser to be created (I'm abusing the term to refer to behavior regulated by "web standards").
(c) because they provide features requested by developers/users. Compare modern JS to JS from 10 years ago, it's pretty clear Google is not the only one benefitting from the new standards.
The question is cooperation between who exactly? A cooperation can turn into a collusion. And all I can see as members of these boards is a bunch of corporations, that are known for using underhanded tactics.