How much does it cost to produce? How good are they on the expected delivery dates? Where does Tesla rank in reliability reports? Selling a lot of stuff means little if the end product is not all that well know for reliability, buyers have to wait for it for e(l)ons and you're hemorrhaging money on each one you produce.
An engineering firm who is very highly regarded in this area states that Tesla has a gross margin of 30% on the Model 3. Highest of any electric vehicle and that is pretty damn high industry wide. Couple this with the news of Tesla approaching the $100 per kWh... the odds are high it is going to be even more profitable soon.
https://jalopnik.com/engineering-firm-that-said-tesla-model-3-quality-was-li-1827632866
Now that doesn't stop the issue of cash burn and the Model 3 stemming the tide. The bet here was always that the Model 3 would have enough margin and enough volume.... quickly enough to hold off the eventual cash collapse. That has yet to be seen and we won't know for probably another year... but the signs are there that the hail mary bet could work.
The delivery dates have significantly improved since they dropped the stupid reservation system. Tesla knows they need cash so they are building the high margin models with the options (smart business, but drops the 35k thing in general). If you get the right options, ~3-4 months is the current experience (Tesla is quoting within 2 now on the performance version). Not much different than ordering a BMW or Mercedes honestly. You can't go to a Tesla lot and buy one obviously, but the timeframe is within ordering custom options from any automaker. German delivery of a BMW takes about 12 weeks to go through consistently for people in the US.
Reliability reports, 100% agree that it is important and Tesla needs to figure that out. It seems the kinks are being worked out in a similar way to how the Model S shaped up. The initial cars were crap and it took 30-40k units to really dial it in. It will likely take more than that for the Model 3, but it seems there is a positive trend there. Now I'd say what is more important than reliability is owner satisfaction... and Tesla is by far the top car manufacturer in that year after year. People love their Teslas when they get them, and that goes a hell of a long ways to forgiving the sins of the reliability. Now they can't count on that lasting forever as they go mainstream, so it is an issue that they have to solve.
I think it is very easy to overlook the accomplishment of selling 15-20k units per month as an upstart automaker in the 21st century. There hasn't been an American automaker to reach this level of success as a start up since Chrysler in the 1920s. Delorean tried and failed hard. Tucker did the same. Yeah they might still crash and burn and there is good reason for skepticism.., that doesn't mean what they have already accomplished isn't incredible. They could shutter the doors today and have produced well over 20 times the amount of vehicles that Delorean did. To me, that alone is impressive.