The idea is to use "MapKit" for maps, not to override it and draw everything yourself... The fact that it's possible doesn't mean it's a good idea.

It is however possible to use Maplibre, Mapbox or some other libraries which I think do support vector tiles.

It’s not a lot of work, like at all. And unlike mapbox/libre you’re are still within UIKit so you can leverage all the existing UI tooling on top of your vector layers.

It much more performant, ergonomic, and requires no external dependencies.