Explaining the fediverse to people is not always easy.
It's like Email
The trouble with this is that few people understand how email works. The sad reality is these days email is mostly Google, since Android stongly guides users to setting up a Gmail account and Android phones are extremely common. This makes the email experience defacto centralized for most users.
Younger users only began using the internet after web 2.0, and so by then email had become defacto centralized.