Does anyone know how much of this is Tesla's technology, and how much Panasonic's? If it's mostly the latter, what would stop Panasonic from providing the same technology to other parties?
There's a big benefit for Panasonic supplying a company with hot products, like Tesla. But outside of whatever contractual obligations they have, there's nothing stopping them.
I implore you to look around at these industries from other sources. If you only read HackerNews, you'd think Tesla is the only company that can make a decent EV (even though motortrend said the Bolt performed nearly as well, had longer range and was $30k cheaper than the Model 60), that no one is close with self-driving and that Tesla are the only one providing this type of solar panel or battery storage solution. These are all hyper competitive, low margin spaces.
Tesla is doing some very cool things, but the unjustified hype is going to blow up in people's faces. Expectations are too high.
The Gigafactory 1 appears to be some sort of joint venture which is bankrolled by Tesla, but operated by Panasonic, where the batteries are produced. The Gigafactory 2 is similar, but produces PV cells and modules.
[1] https://www.sec.gov/Archives/edgar/data/1318605/000156459016...
[2] https://www.sec.gov/Archives/edgar/data/1318605/000156459017...
Confidence in Tesla is high because people like the brand. Panasonic similarly works hand in hand with Tesla because they're confident the value of the Tesla brand. People will read that motortrend comparison and still buy a Tesla - because the bolt is ugly and looks like your lyft drivers car, and because they want a Tesla.
The idea that Tesla has unjustified hype is not a novel position to take and I don't know why it would serve as a good position to snipe at Tesla when it hasn't worked at all in the past. (see recent short sellers woes)
I think you can think of Tesla as "Standard Lithium" - like Standard Oil in the past, they built a giant refinery (The GigaFactory) to give economies of scale and built many channels of distribution to sell it all + compliments: cars, battery packs, solar, etc.