Will you be able to use AMP without ever touching Google servers/services? So it actually works like said subset of HTML to clean up the mess we're in. You have to force those things directly in the core, you can already make pages fast with current tech, that's probably why they also talk about ads in the spec. At least for non-SPAs (I wouldn't complain about another layer for SPAs that cleans up the rest of the web). You can't even open most of the official AMP project pages and docs with JS disabled, that's often a red flag.

I'm not really an expert on AMP, but would only support it if they actually made things better without pushing for their own services or pull things like AMP for Gmail, variations of EEE.