avhon1
Unable to answer "What’s the surface here?" for https://osm.org/way/630632150 via StreetComplete 42.0:

Carpeted. This section of the footpath is inside a covered hallway. The doors to cross are not locked, but the doors to go into the buildings at either end of the hallway are.

Attached photo(s):
https://westnordost.de/p/87027.jpg