One of us, one of us!
I came here to say pretty much the same thing. It’s even more interesting when you’re working with a future-of-the-real-world setting, and so you actually have to think about how present-day cultures might evolve into the future.
I think this would be more meaningful if things cash flow and hirelings had any reasonable purpose in 5e. But the reality is most players will have a pretty stable cashflow by level 5, and most campaigns simply don’t have a meaningful role for Hirelings to play.
So like, I could see this being a thing in Waterdeep Dragon Heist, which encourages you to acquire a home base and then take a side in a gang war. One building, 4-5 rooms acting as a bastion for each player? I guess. But it’s essentially making mechanics for something a lot of DMs did already, and a lot of other campaigns simply don’t have a good basis for this.
I’m also kind of underwhelmed by the attacks mechanic. “A random special facility is shut down for your next bastion turn”? So like, I can’t ever actually lose anything I put into the bastion, it just stays there even if I have literally no defenses, the attackers overrun the place, and squat in it for 7 days?