It's a mapbox mvt, which is protobuf. It contains the OSM data (obviously), but it's a specific format that's in wide use (mapbox-gl, maplibre, and many other open source versions). There are similar versions in pmtiles, which is basically the same thing in a http range friendly big single file which can be hosted on S3-like storage and used directly.
The difficulty is that the stack for rendering vector tiles in the browser is different than the legacy vector->png generation that's been done for ages.
The difficulty is that the stack for rendering vector tiles in the browser is different than the legacy vector->png generation that's been done for ages.