If the tools for discovering and subscribing to communities could be improved so it becomes dead easy to subscribe to communities on any instance from any instance, that might not need to happen.
Right now the process of having to search for each community and subscribe is too clunky. And if someone posts a link to another community it often comes up in a format that takes you to the other instance, where you have no account so can’t subscribe. We need a way to share links to other communities that incorporates an easy “subscribe” button that talks to your own instance.
It would be nice to have some index or search result page that lists communities on all instances, with a subscribe button next to each.
If these things can be smoothed out, it won’t matter too much which instance you have your account on, so that will be less of an obstacle to new users.