One way is to compel (via legislation) all social media networks to speak a decentralized protocol.

This seems both feasible and practical. Sure, it will have problems - from the point of view of ___ platform regulars, it would be like an 'eternal September' of how everything got worse once those awful people from Other Platform were able to cross-post but that would probably spur innovation in client-side filtering.

I like Mastodon (apart from the me-too-ism of calling Mastodon posts 'toots') but agree that Fediverse offerings are mostly like desktop Linux or cheap fusion - they'll be really great when one of them takes off. The sad fact is that there are lots of designs that are as good as or somewhat better than the big platforms, but none of them are categorically different.

Consider the evolution of social media:

Newspapers: Anyone can write to editor

Telephones: Anyone can talk to anyone

Usenet: Anyone can post in a hierarchy of topics

Web: Anyone can have a webpage

Google: Anyone can navigate the web

Blog: Anyone can have an opinion column

Youtube: Anyone can be on TV

Twitter: Anyone can amplify their random thoughts

Facebook: Anyone can publish a yearbook

GitHub: Anyone can be a tech star

Instagram: Anyone can publish a magazine cover

Snapchat: Anyone can look like a celebrity

LinkedIn: Anyone can be a professional

Tinder: Anyone can be a porn star

Bitcoin: Anyone can be rich

Crypto: Anyone can be a central banker

Periscope: Anyone can be be a TV reporter

Tiktok: Anyone can be iconic

Fediverse: Anyone can run a social network

Obviously I'm being very tongue-in-cheek here but what makes a platform stand out is providing the ability to do something different that was not previously available, and either socializing that or making it stupid easy to do so - ie 'Love XYZing? Do it here and get noticed.'

If your offering is 'YYYYY for ZZZZZ' (where Z might be anything from 'hermits' to 'everybody') then you'll get some rapid adoption because it's easy to understand but it will plateau pretty fast. The secret of success is making people say 'No way, how does that work' and being able to say 'easy just Do The Thing and press this magic button.' The Thing has to be something whose benefit is immediately comprehensible but whose availability is extremely limited or outright fictional.

>90% of social proposals offer new and improved buttons, but experience suggests people are quite tolerant of inferior buttons (network quality, uptime, etc) as long as Doing The Thing is still novel; you work on the button in between getting your first and second competitors. If many people hate or don't get The Thing You Do that's actually a plus because all the misfits will flock to your platform and give you their cult-like loyalty.

I think the mistake with Fediverse stuff is the pitch that 'you can have total control/do it all' - if I wanted that I would have become a sysadmin, but the reality is that everyone wants to use email but hardly anyone wants to run their own SMTP server, much as most people want to drive fast cars and look good doing it, but relatively few choose to be mechanics or take up the risks of competitive driving.

You need to have a benevolent dictator/Santa Claus/Mommy/Team figure(s) that people can coalesce around, who gives you both a way to Do The Thing and permission to use it - it's 50% technical innovation but also 50% validation. People like having a person they can connect with both for technical requests/gripes and to serve as surrogate parents/friends. A socially oriented product/platform with no personalities attached is a contradiction in terms; it might be fun to play with but you probably won't tell your friends about it.

A: I have feelings about this
B: Me also
A: The world should know of my feeling
B: Indeed
A: I shall now Do The Thing
B: WHAT
A: Yeah check it out
B: WANT
A: Sign up like so
B: I am momentarily fascinated, who made this
A: Bro and Sis, they are super cool
B: How I do a thing...
A: Like this, it is the Bro and Sis way
B: I feel my life changing around me
A: Now you are family
B: Best friend would love this

If your pitch (to anyone) is 'Look at This Thing' or 'That Thing but different' or 'Have you tried The Other Thing' you are ultimately soliciting someone else's attention and the results will be proportionate to how people allocate their limited time. What you want instead is to improve an existing moment in some unexpected way, and then convey a sense of permanence or continuity in relation to the improvement. The witness to/beneficiary of the improvement will then be motivated to trace The Thing back to its source, to whom they will offer publicity/ suggestions/ technical help/ money or whatever.

To conclude, the breakout path for the Fediverse is not to solve this or that problem of social with a nicer button; when you offer solutions to a problem some may appreciate or even love it, but the appreciation often comes with a 'but...'. Rather, it is to build Fediverse technology into some novel object, and use federation to solve the (inevitable) issues that arise as the novelty gains in popularity.