That restriction is needed in some way to prevent that building being a way of teleporting stuff across the planet. They did relax this in 2.1 and allow you to build extensions to that building where you can add inserters and use belts/trains.

I'm going to restrict my commentary to the base game, both because you're deliberately ignoring the stuff in the Space Age expansion, and because I've not yet gotten to the new stuff in the expansion. While the following might sound like a "gotcha!", it isn't:

> I get bored whenever there is only one way to do a thing and no room for a player to invent alternatives.

There is only one way to process iron ore: put it in a furnace. There is no way for the player to invent alternatives. There are only three ways to make electricity, and two of them require you to boil water. There's no way for the player to invent alternatives. There are so many examples of places where stock Factorio permits you only one way to do a thing and prevents you from inventing alternatives.

> The system for moving between planets is locked down. ... And that system is deliberately designed to defeat scaling.

All of the systems for transporting materials are locked down... it's hand-transport, belts, bots, trains, or nothing. Hand-transport's godawful scaling is why you build everything else. Bots are deliberately designed to scale incredibly poorly and belts to scale pretty badly, which is why you're -as it seems like you'd say- forced to use trains to transport materials over very long distances.

> The tech tree become more rigid. Exploration must happen in a more specific order. And then the graphics department takes over, adding more and more objects until a previously huge and open world is a tightly cluttered mess.

That hasn't happened to Factorio in the thirteen years that Wubi has been working on it.