I've got to say, one complaint I have these rules is that they don't feel linked to the game world at all. They're just arbitrary 'player mechanics'. Like the facilities being unable to be bought but materialise onto your fort when you level up.
5e has always had this problem, but it's been doubled down on over its lifetime. Players are using such a different set of often arbitrary rules compared to the rest of the world.
Of course they aren't linked with the game world. Almost no game mechanics throughout D&D are. I mean I'll keep saying it until people start actually realizing or accepting it... but the game mechanics of D&D exist to play
the game of Dungeons & Dragons. The board game of Dungeons & Dragons. Where you roll dice to get better numbers compared to other people who are rolling dice trying to get better than you.
And while the results of those dice rolls gets
translated into a semblance of story beats... those rolls are not in any meaningful way, shape, or form actually
illustrations of the narrative of the world being played in. And if (general) you try and connect the two... you will ALWAYS find the disconnects between how the game mechanics work (for the board game to play correctly) and the flavor and story of the campaign you are playing in.
These Bastion rules now exist for there to be a downtime "mini-game" for players to play in building and running some function hall. But they do not illustrate the actual lived-in experience of owning and running a function hall
within the campaign story. Because as everyone has been saying... you can own a function hall
at any level if you, the other players, and the DM all work together to weave that story... or a character can do so
without even needing PC levels-- in the narrative of the campaign, some NPC just
does it. No game rules necessary, the DM just says "Bob The Bartender owns and runs a pub."
But because D&D is in fact a game and not just an improvised world-building and story exercise... the designers of D&D will occasionally make up game rules that allow a person to "play" them, as a way to
gamify what would otherwise be done by players improvising together in world-building and story. The designers of D&D do not expect their players to be competent long-form improvisers who can actually create pubs in their stories whenever they want and create drama from it out of whole cloth. That asks way too much from players. Which is
why they gamify it-- to allow the non-long-form improvisors out there to recreate these stories using game rules to a certain, small extent. But those game rules are just a facsimile of actual narrative storytelling. They are not actually a part of it because they are merely a game, and not a story.
Which means if a person finds the Bastion game rules disconnected from their story... then they probably shouldn't use them. And hopefully... the players at that table are competent and confident long-form improvisors that they all can just "make it up" within their campaign's narrative and not need "game rules" to follow in order to do so. If they can do that... then their party can start their games owning a keep even at Level 1 and just playing sensibly, equitably and not try to rig the story for their own benefit.