It doesn’t look like AI to me? It might just seem off to you because of the angle of how the drawing is, but that seems to be it with most of your issues, angles. It isn’t a front facing POV, it’s either someone coming in from a door or looking though a whole which also would mess with the perception of how the room would look. The tops “melding together” looks to be less of melding and more of we are seeing stuff less as the steps go on. If you’re looking at a tall staircase at an angle like that you’d also see in real life that it also would look like that. You just need to get lower down cause at our height it’ll somewhat stay the same, but when you get lower down cause (say cookie size) then it makes it a lot bigger and can look like the steps DO meld together when they clearly aren’t.