I'm a little surprised it's taken this long for OSM to get there, the basic technical pieces were available over a decade ago. I don't mean to complain about the free map service, it's excellent, and I recognize they focus more on the editing and data ownership. Serving is hard and expensive.

Mostly I wonder how much MapBox's dominance for a few years disrupted other efforts.

The new stack has some unique feature like the vector tiles being minutely updated directly from OSM mapping changes.

There are still issues to fix as it is still only a technical preview.