I want to thank @hermeslispegistus for bringing up the very valid issue that Mastodon's burgeoning popularity may damage the federated system. The responsible way forward is to promote federation in every way that we can.
Other options worth considering are the ones that @Gargron mentioned in his welcome post on Medium, http://icosahedron.website and http://social.tchncs.de
I know there's a temptation to believe in the idea that there can be one simple, easy-to-explain alternative to Twitter that works for *everyone*, but the truth is there literally can't be.
Federation is, in a way, a socialist approach to dismantling the control that Facebook and Twitter have over the way people communicate online. It can be hard to explain, but I truly believe we'll develop the language quickly enough. We figured out how to explain what the fuck a social network even *is* in the first place, after all, we can do this too.
@kadybat it's important to note, however, that "make your own instance" is still a solution that is only accessible to certain folks, and the fediverse doesn't really respect this material reality but rather assumes every used has the resources and ability to roll their own.