[wg0]

This seems like that infamous <marquee> tag [0] to me that felt good and amazing at the time but later turned out not to be a good idea.

[0]. https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/...

[riffraff]

did the marquee prove to be a bad idea?

I think it was subsumed by later developments (javascript), but the issue with it AFAIR was just that it wasn't useable in all browsers, not that the tag per se was a bad idea (as much as scrolling text can be).

The situation with the model api seems different, more like the AMP spec.