Your definition of email is transparently unreasonable, if you insist it can only refer to what IMAP and SMTP provide. When do you freeze IMAP? Version 1, 2, 4, 4rev1, other? Are SPF, DKIM, DMARC part of “email”?
I said you seemed to be fixing on first-party software because a lot of your arguments about centralisation of power and such and assumed motives of companies pushing JMAP only make sense in that light. I’ll say it once more: by its design, JMAP distributes the power, supporting usable decentralisation better than IMAP/SMTP/CalDAV/CardDAV/&c. Adoption is limited yet, but that doesn’t change this fact.
As for Gmail: you’ll get a second-rate experience if you don’t use a Google client or Google-specific APIs. Dodgy IMAP (partly understandable—when they started, IMAP didn’t support the concept of labels and so they had to make some kind of workaround—but IMAP has very obviously been a second-class citizen through all Gmail’s history). No notifications unless you hold an IMAP connection open (which you can’t on mobile platforms). The necessity of Gmail-specific authentication (or else some users won’t be able to use it at all, and the rest must jump through increasingly-scarified hoops). That’s what Google is pushing. Gmail’s dominance has absolutely involved locking people to first-party clients, and IMAP/SMTP support is a concession. JMAP is nothing like all of that.
I said you seemed to be fixing on first-party software because a lot of your arguments about centralisation of power and such and assumed motives of companies pushing JMAP only make sense in that light. I’ll say it once more: by its design, JMAP distributes the power, supporting usable decentralisation better than IMAP/SMTP/CalDAV/CardDAV/&c. Adoption is limited yet, but that doesn’t change this fact.
As for Gmail: you’ll get a second-rate experience if you don’t use a Google client or Google-specific APIs. Dodgy IMAP (partly understandable—when they started, IMAP didn’t support the concept of labels and so they had to make some kind of workaround—but IMAP has very obviously been a second-class citizen through all Gmail’s history). No notifications unless you hold an IMAP connection open (which you can’t on mobile platforms). The necessity of Gmail-specific authentication (or else some users won’t be able to use it at all, and the rest must jump through increasingly-scarified hoops). That’s what Google is pushing. Gmail’s dominance has absolutely involved locking people to first-party clients, and IMAP/SMTP support is a concession. JMAP is nothing like all of that.