GC HQ's technically do reside in real buildings, you just can't walk to it lol. Either way though, it's definitely a step behind it's predecessor. Bastok had it's Metalworks, Windurst had it's Star Tree, Jeuno had Ru`lude Gardens, Sandoria had it's Cathedral and Palace and Aht Urghan was similar to what XIV is like, but XIV was being produced around that time period which is why they cheaped out on it.

They do have a small appearance like going to Maelstrom you can see the flags and whatnot but given that there will be 'Free Companies' for players at some point in 2.0, it's likely GCs won't be central post Umbral Era events.