Just being devil's advocate since I also don't necessarily agree that TSwift could build a venue in every market, but there are plenty of large-scale events that use open fields and tents and aren't going to cost billions to setup.
But to build / buy thousands with a real estate value in the 100s of billions you would need something like a EFT.
A venue is more than having a place, it's having everything necessary to handle an immense volume of people gathering, acting, and dispersing from a single location in a safe and orderly fashion.