They don't necessarily build the best cars.
As a tesla owner I'd say they are better bult than most American cars, on par with German but behind the Japanese.
Five years ago I would have agreed that they don't have quality cars (even though they were still the best EV). I was refusing to go near them for several years after test driving a "classic" model S with rattles and squeaks and all that, but at least in my own car (2019, model X "raven") these kind of things are non-existent.
Edit: On topic, I also think that the stock is crazy high.
Yea the stock is insane, it'll be interesting to see where it goes.
Where I work (in Norway) about 10% of the employees have teslas and there are not more issues than most fossils except for the Toyotas perhaps :)