They care in the sense that they want [Facebook|Youtube|Twitter|Instagram] without the enshittification. When told about alternatives with some promise that aren’t exactly that, they often don’t have the mental energy to explore.

Correct. No one can use something that they don’t know about.

Right now Lemmy is really best for centralized populated instances that have a similar experience to being on Reddit. Federation is a bonus. There are a lot of problems with trying to access content on other instances. Weirdly, the name of the sub is not shown in the URL for posts. Someone might be able to create an alternate web client, but that adds another layer of complexity for people who just want to run the site.

The main problem with federation is that there’s no “site” that people know to go to.

I think they care the other way around. Many people admire big corporations and either work for one or wish they could. Just think about Apple fans as one example. So if you tell them there is Reddit, which is run by a company for profit, and there is Lemmy, which are a bunch of servers run by computer nerds for the joy of it, this will actively draw many to Reddit.