Open in what sense? For example, there's no open standard (to the best of my knowledge) for the HTML used in emails right now and different email clients render HTML in emails differently.
On the other hand, the protocol itself is standardized, but AMP is not working on protocol level.
AMP for email has support by Outlook, Yahoo, and Mail.ru, so it very much isn't under Google's control.
https://github.com/ampproject/meta-tsc
I would hardly consider Yahoo to be a leader in anything at this point, not sure about mail.ru. From an outsider's perspective AMP looks Google controlled.
It looks like from your comment history you are part of Google's AMP team. It would be nice to disclose that.
The TSC requires majority consensus. Google does not have a majority.
I remember you talking about how transparent the process is, but, alas, you never described it. And to quote another member of the discussions back then, anyone raising concerns:
> were closed or locked, and the head of AMP blocked us.
You being the head of AMP, of course.
mail.ru is owned by the same mafia group, that controls majority of Russian internet. They are either very stupid or want the same thing as Google (to destroy email as we know it). It is probably both.
Participation of mail.ru implies, that Russian mail providers won't ban Google in retaliation for this crap (neither on SMTP level nor via country-wide firewall).
Suggesting any part of AMP is open still feels very disingenuous when you recognize the monopoly position of the company spearheading it.
...which means nearly nothing.