Follow people and hashtags and interact with them and you'll get followers.
That sounds like a convoluted method of self promotion, almost like SEO fake engagement, just to be discoverable. And if everyone on the network had to do this to be discoverable, how can I trust the discovery methods to find people worth following?
And if the cross instance discoverability has these kinds of hurdles, then the promise of federation isn't going to pan out.
At least with Lemmy the nature of the platforms, users following a smaller universe of potential communities, makes each community much more easily discoverable for people who don't necessarily want to be active posters. Mastodon's user-focused follow is much more limited in seamless federation.