I don't know why being able to build my own space ship and fill it with multiple functional systems exactly how i want it is so appealing to me.
It fires my neurons so much getting to make a compact living workspace and then fly around visiting other places.

Specially since you get to move around your carefully crafted spaceship and enjoy your own work.
Not a lot of games do this, and when they do, its usually dogshit.
Starfield was close to this, but the ship flying mechanics were a fucking joke.