There's no point in migrating to some perfect encrypted federated free software platform and being alone because everyone I know is still using Instagram.
If everyone went by that logic no one could ever stop using the social media sites they are using today. If you've found a good platform your best bet is to get people to use it in addition to the bad ones they use now and as more people join and use the better platform people could find themselves using the old ones less frequently. By enjoying and getting used to having the benefits of the new platform they could grow increasingly frustrated by the limitations of the older ones.
As long as the perfect encrypted federated free software platform is at least as easy to join and use as the old one asking a friend to add one more app to their rotation wouldn't be putting a huge burden on them.
These aren't problems with screenshots of text (although others have done a pretty good job in listing those) or even problems with computing. These are problems with shitty social media platforms that want to take control from their users, and with the users who accept those kinds of limitations. Stop using bad user-hostile platforms and they'll either improve to win back users or they'll become obsolete and die as people flock to better alternatives.