Income potential at the individual level is likely limited. There could be a honeymoon period where early adopters are getting paid for a good number of rides at good prices. That attracts more people to do it, putting more vehicles out there. This leads to each vehicle getting less rides.
There's too many situations that leave me without my vehicle when I need it, either because it's actively delivering someone to their destination across town or it's out of service while being repaired / cleaned / etc.
I am sure a lot of people would try it, but it's a sucker bet for the vehicle owner over time. They get all the risk and much of the cost, but only a part of the revenue.
If you remove the "driving vehicle yourself" component and have it drive itself almost for the entire day, on it's own, while you're busy with your own stuff, how can it become a worse deal?
If I buy a Tesla and put it into robotaxi mode, I am not there. I am not making decisions about how the vehicle should be operated. I am not in control of ride selection. I can't use my car to store personal items, unless I'm OK with the risk that they might be stolen.
There's a huge number of problems that could happen to any robotaxi vehicle. When that vehicle is part of a fleet, it's no big deal to the fleet to lose one vehicle. When the fleet is owned as a unit, the costs of those problems are spread out.
As an individual owning a vehicle that intermittently joins a fleet, the fleet still feels the same way about my vehicle, it's no big deal. But losing my vehicle is a huge deal to me. It is not a class of risk I would want to take on unless the revenue is insanely good, or Tesla finds ways to assume the majority of the risk and minimize the financial and convenience risks I have to take on. Both of those paths substantially impact whether it would be a viable business for Tesla.
The only way to make it a good deal for Tesla is to make it a shitty deal for the vehicle owner, and vice versa.
2. Now owning the assets themselves gives you much better margins and easier access to capital. It's no coincidence that all hotel and fast-food chains use franchising models.