Does this not require a massive database of tiles?

I ask because I've been looking to self host some sort of map tile server and they seem to have database in the hundreds of GB.

Good question. Corviont is region-focused (you package one region), not "host the whole planet". Hundreds of GB is usually the full planet at high zoom / lots of layers.

Also it’s not one giant tile DB - there are 3 datasets:

  - map tiles (PMTiles)
  - routing tiles (Valhalla tiles)
  - geocoder index (SQLite)

For small countries like Austria/Slovakia, each is typically hundreds of MB.

The size of the tiles will depend on how much detail you want.

Maptiler has a bunch of datasets, anywhere from 385MB to 527GB but the OSM dataset is only 70GB. (MBTiles format)