Calling a Model 3 an econobox is just plain wrong, and is obviously intended to insult rather than engender polite discussion.
As for interior fit and finish, I really don't see a difference between the Teslas and the Germans. Individual cars may have individual problems, but overall Tesla, BMW, Mercedes, and Audi put together quality interiors. If your argument is that a Tesla is less luxurious because it's eliminated most of the buttons, knobs, and controls, or has synthetic leather rather than real leather, I'd call that a specious argument.