If you look at how RSS fell from use, there were two major issues. On the user side, users had to go out to find content as there wasn’t an inherent way to search for content within the system. On the creator side, creators had to deal with advertising themselves to users and they had to handle the monetization by themselves.
Social media created the algorithm to find content and developed some revenue sharing with creators.
If federated media takes off, it will probably look like Threads or Truth Social, where control of a front end monetizes development of the platform.
I’m going to use your car analogy, but tweak it.
People are looking to sell their car and buy a new one. One car acts like their old car; it has automatic transmission and there is a network of mechanics to take the car to in case something breaks.
The other car has a manual transmission. The car requires regular maintenance to do done by the owner like weekly tuning of the timing belt. There aren’t mechanics, but car clubs where people will give you advice on how to fix your car.