But mind: openstreetmap.org is ment as a developer site, for developers to see their changes quickly. The official idea is that other people should take the data and do "nice" things elsewhere. But of course reality is that users want to use openstreetmap.org as alternative to Google maps ...
I'd love to see OpenStreetMap.org be more directly useful to more people, rather than only as a "developer site".
Thus, we get a built-in editor (less friction, yay/too rudimentary, boo) and popups (OSM events, yay/Popups are now everywhere, boo). And endless discussions on "this should be more/less prominent."
I don't think there's any official edict, but the approach "I don't like this and I'll make my own version" is at the very least workable (as opposed to, say, Google Maps).
The main purpose of the maps on the site is, besides showcasing some topical uses of OSM data, rapid feedback to contributors, which is something that required specific development so that can be provided with vector tiles too.
The 'late to the game' narrative seems to be a bit misplaced in any case given that OSM data has powered essentially all vector tile use outside of Google over more than a decade.