You are generalizing too much here. I know many who have tried out a product only after seeing its ad. Ads can give plenty of returns to brands. But targeted ads which even exploits our most intimate conversations are really bad news for our right to privacy.
Many people forgot, many others now think that he is the villain of the story just because he did what he had to do to save his life, a whole lot don't care because 'they have nothing to hide'. For what it's worth, people who actually care about their privacy is a very small minority in pretty much all countries.
If you were using Signal just for SMS, none of your messages were secure anyway since the SMS protocol itself is not–defeating the purpose of signal. And if you had already convinced people to install Signal by using SMS as a caveat, you can just continue contacting them through the app.
I was able to convince pretty much everyone who matter in my life to install Signal and they all love it because WhatsApp has become too cluttered and spammy.
This is one of those incidents that is infuriating for the parents when it happens, but will then end up being a story that they cherish and keep telling everyone they can for a long time.
You don't need to do that if that community is already federating with your instance. If its not, it might take a little while for the federation to actually start after you make the search (based on the server infrastructure of your instance and the remaining queue). Try searching again after a bit and it should be there. These quriks should be solved as instances become more stable, and Lemmy/kbin gets further developed.
Yes, that will show you all the communities/magazines that your instance has already discovered and have started federating with. But if it is a community that hasn't been discovered by your instance yet, you will need to search with the link for it to start federating. And once even a single user from an instance does that, the community will be visible to everyone else as well.