> Unless the automation creates free trucks for all to use

This is indeed pretty much the basis for these questions to arise. Not free of course, but such marginal cost that ownership would not mean much.

When instead of 50 cars / trucks, you only need 15 and their cost is shared among the local community, with the price of buying one / maintainance very low due to automation, it will make sense to have this kind of system.

Doesn't mean ownership would disappear, simply that for most people it would be more convenient / cheaper to use this system, and as such most people would choose to do so.