Our brains are dumb, and they really like having a few clear places to hang their trust.
When we're deciding whether to invest time, effort, and especially money in something, we look for a trust hook, an entity that we can evaluate for trustworthiness. We can then judge that trust hook using our own direct experiences, or by social proof, or by ambient familiarity with a name (availability heuristic).
The most well-established trust hooks are corporate brands. A company like Apple spends millions in advertising, and probably far more in product execution, giving people a central concept of "Apple" to trust that they'll get privacy protection, well-made hardware, and things that "just work" together.
This is pretty basic stuff. But what happens with decentralized or federated protocols, things like Mastodon, Matrix, and blockchains? The whole point of these things is that there isn't supposed to be a central entity, so where do people hang their trust?
With Mastodon, the trust hook is the "instance" that someone uses to sign on, whether it's the default mastodon.online, or a smaller community like hackers.town or Friend Camp. Even the larger federated space is usually referred to as the "fediverse" or "fedi", rather than people hanging much importance on "Mastodon". Because the local community is the primary hook, the whole concept of "getting started with Mastodon" is a bit awkward and over-general. It's like asking the question "how do I get started with a hobby?".
There's a similar dynamic at work with blockchains. You might hear about Ethereum on the news, but when it comes time to hang your trust somewhere, most people will end up having a relationship with something that feels like a bank or brokerage, which is part of why Coinbase is valued so highly—they are one of the best-known trust hooks for cryptocurrencies.
Yes, you could go down the path of putting together some scheme of hardware wallets with metal-punched seed phrase backups, but in that case you're probably hanging your trust on "your friend who's into crypto", in the same way that in the early 90's you might have gotten a Windows box built from parts by "your friend who's into computers" instead of Dell.
What's the commonality here? It seems to come down to the on-ramp: what's the main picture in your head during your first steps to invest in a new thing?
So when bootstrapping new decentralized or platform technologies, make sure there's a clear place for people to hang their trust when they're considering coming on board.