There are absolutely no standards at all when trying to code emails, it takes hours trying to make something that remotely resembles the same thing on every engine (Microsoft outlook rendering emails with their ms word engine, google doing all sorts of different things on desktops vs phones) - and hours more of testing and tweaking css and markup hacks to make them readable. Although this is another puzzle piece to s…
That's pretty much how I introduce people to email development, and AMP for email isn't going to solve for that in any meaningful way.