There are tons of challenges for Mastodon to overcome though. It’s not able to aggressively market itself because it doesn’t have a budget to challenge the big social media networks without getting actively crushed by them. No commercial interest wants to move to the fediverse because they can’t exploit it and use it as a marketing platform. It also can’t afford to strike deals in countries with no net neutrality laws (in many poorer countries, facebook can be used entirely without a paid internet subscription; which effectively makes facebook the de-facto internet, as people can’t afford a paid subscription to access the rest of the internet). I.e. when facebook removed their free option in India, there was a massive surge of users coming to Mastodon, unfortunately this wasn’t capitalized on (in fact, it had a lot of resistance), and the momentum died down.

Additionally, some of the fediverse is currently being supported and funded by the EU, who also officially hosts a few services within the fediverse. A handful of people within the EU wants to end the american commercial monopoly of social media and are pushing for the fediverse to replace them. But for that to happen, a lot more need to change. For one, if they finally manage to ban facebook in EU, you could see a good surge of adoption for the fediverse if marketing is done right and have an actual budget (the social media called ‘Band’ saw a big spike when facebook started banning a bunch of hobby groups - which was a missed opportunity, that should have been the fediverse, not another commercial ‘facebook’ clone, but the fediverse don’t have a budget nor convenient apps and resources to make people jump ship over here - i.e. if the team behind Mobilizon didn’t focus on france first-and-foremost, with the single biggest server being french (because the devs own server is always the ‘trusted’ server), and had an app available, Facebook/Band could have had actual fediverse competition).