Worth noting that these are vector tiles and not raster tiles, so zoom levels work slightly differently. Generally you don't need as high zoom level with vector tiles since it is much easier to 'zoom in' on vector data than on raster data. A vector zoom level of 14 stores the data with roughly 50cm precision which is good enough for most casual mapping uses.

Ah quite right, I see they're mvt. In that case it might actually be usable.