Honest question, have you personally been inside a Tesla or did you form your opinion through YouTube videos, car reviewers, and anecdotes from other people?
I wouldn't say the interior is on par with a typical "luxury" vehicle by any means, but I don't think it's bad either.
Edit because I think this is relevant:
A few weeks ago I made my first large mess in my Model Y. While getting out of the car I slipped and spilled a soda, a pizza slice, and 5 wings all over the seat and floorboards. I had root beer going down the walls, pooling in the seats, saturating the carpet, etc.
And I have to say, that is the EASIEST interior I've ever cleaned in a car. It took me about 15-20 minutes and it was spotless. The faux leather is sealed nicely so the soda didn't absorb through the stitches or run out the sides, the trim pieces were fit together snugly and I didn't have to go digging to wipe soda out of the door jamb or seat tracks. The fabric on the B pillars and headliner didn't stain, and it was easy to get to any spots I needed to. It doesn't smell like any of the food afterwards either.
I've spilled shit in a bunch of other cars and trucks of all shapes and sizes, and the Tesla was the easiest to clean up by far. I was impressed.