They are boiling frogs: https://en.m.wikipedia.org/wiki/Boiling_frog

Little changes over time, so you don't see the end game right away. Signed exchanges and further hacking up / hiding the URL will come. This change only hides some of the URL, with a hover action that shows it again.

Requires implementation from the amp site as well I think, but here's the spec they introduced to allow for it: https://caniuse.com/#feat=sxg

It's called signed exchanges.

https://amp.dev/documentation/guides-and-tutorials/optimize-...