Vector tiles can be considered as small databases containing features within the tile. As such, vector tiles contain these features "rendered" taking into account zoom level at which they are used. There are positive and negative aspects of this approach, but, in the end, looks like positives (fast and on-device rendering of the maps) outweigh the negatives (having the same data included in multiple tiles along zoom levels, long imports of data). [stressing positives and negatives is my take, not very thorough, probably].

Now, while we can get access to vector tiles with the layers described, we also need stylesheets that would process the data and result in a map that you could see. For example, Mapbox GL styles that you see come with a stylesheet that refers to vector tile data on mapbox server. Same with OSM Scout Server: styles (https://github.com/rinigus/osmscout-...apboxgl/styles , generated from https://github.com/rinigus/mapbox-gl-styles) are referring to layers in vector tiles served by the server.

I haven't seen any stylesheets provided by Thunderforest. Which probably means that we have to design it using their data. For that, one could read up on styles (https://docs.mapbox.com/studio-manual/reference/styles/) and use Mapbox Studio or some other tool to generate the style. If the style will be available, I don't mind adding it to Pure Maps