I fully admit it's a bet rather than investment if you're putting money into Tesla and I wouldn't be putting in any money I was relying on into it. Excess cash that's going to luxury/fun purchases I have no problem with. This isn't necessarily an argument against you, because I agree it's speculative, but for anyone that looks at the stock and says "I don't understand this":
Uber/Lyft
When you compare a Tesla autonomous driving service versus a company like Lyft or Uber it doesn't really match up for a couple of reasons. Tesla could undercut Uber and Lyft on price, because the maintenance/cost of a mile driven for an EV is substantially lower than for the average car. Then you tack on that the service does not have to pay an operator for their time (just the time of their vehicle) and they can be cheaper and more profitable than Uber or Lyft. Almost to the point that it would be cheaper for a person who owns a combustion vehicle to order a Tesla "rideshare" (without actually sharing the ride) than it would be to drive themselves.
There are a lot of trips that a person (many females) wouldn't use an Uber/Lyft for because of safety reasons that they would easily use an autonomous vehicle for. Again, purely speculative, but that's the multiplier for that line of business. You could imagine a subscription service that reduces the cost per trip and gives priority to trips, which would normalize revenues.
They have to achieve autonomy for any of that to come to fruition.
Battery Manufacturing:
The largest battery manufacturers in the world are currently delivering batteries largely for smaller portable devices. The demand for batteries is expected to 10x or more over the next 10 years. Plenty of growth potential there. And it's not so much battery manufacturing that is Tesla's advantage, it's that they've secured technology, securing and growing capacity with partners, which gives them an edge over other auto manufacturers on cost, leading their vehicles to be cheaper for the value long term.
Auto:
The cost of an EV is projected to reduce to price parity with a combustion vehicle within 5 years, and the margins on sale are better than most auto brands, comparable to most luxury auto brands. With the cost of manufacturing an EV falling (much) faster than a combustion vehicle, you could be looking at a company selling vehicles in the price range of a Camry with the margins of a BMW. That's worth extra over what current auto valuations achieve.
App store:
This is really just a kicker over auto, and I doubt will ever be a substantial source of revenue, unless you include software sales for self driving.
There is also energy delivery/storage potential with operating massive batteries and trimming price fluctuations throughout the day, which hasn't really been mentioned.
Here's the Ark Invest article on how they came up with their 2024 base case price target of $7000, which is a pre-split price target ($1400 post-split). They have a bull case price target of $3000+ with a 25% likelihood by 2024. They've grown more optimistic about Tesla given what they've done through this year/what other auto manufacturers haven't done. More of a what's the thinking from people smarter than I am.
https://ark-invest.com/articles/analyst-research/tesla-price-target/It may be a massive bubble or it may be a massive bargain. No one knows, but I look at a guy that landed a rocket and made electric vehicles mainstream enough that Ford is making an electric F-150 and I'll take a flyer bet on him.