I don't own a Tesla, but I have a relevant anecdote related to your post. I rented a Model 3 in Switzerland and while the car was drivable, I felt that the interior was cheaply made, giving the impression that I was driving a toy car.
The car had a lot of plastic and whenever I drove over bumpy roads, there were cracking friction sounds everywhere. Additionally, the acceleration was extremely sensitive, making it difficult to maneuver in tight streets.
Your BMW 1 series is considered a luxury car. A new sedan is close to twice the Model 3.
Tesla is not a luxury car company. You pay a premium for the electric part, and put up with everything else.
They took a risk that nobody else was willing to make and proved a market. We're in a better place, ecologically speaking because of them. Their cars are also cheaply made. Now that manufacturers that know what they're doing are competing, Tesla is in trouble.
Tesla has always cut corners on everything besides the powertrain because batteries were so expensive. Now that battery cost has fallen so much, they're upgrading interiors, starting with the Model 3 refresh.
Aside from possibly BYD, other manufacturers have no particular cost advantage over Tesla in BEVs. Ford and GM are still losing money on each one they sell, and have cut production for next year.
I agree on the Model S, some of the interior feels cheap (but some does not). In particular the panels around the door interior don't mount very well or stay put. The rest of the interior seems good though. This coming from an Audi A8, which had a really great interior.
The car had a lot of plastic and whenever I drove over bumpy roads, there were cracking friction sounds everywhere. Additionally, the acceleration was extremely sensitive, making it difficult to maneuver in tight streets.