Using a phone as a mini computer was possible. Downloading and using apps happened. I even used offline maps. It was still the preserve of nerds while regular people "couldn't understand why you'd use a phone to do anything other than text and call".
SUDDENLY once it became seamless and trivial to set everything and it was all brought together on a device that was aesthetically pleasing and ergonomic demand rocketed upwards. It turns out that regular people very much wanted a mini computer in their pocket.
This all took me very much by surprise coz almost everything that was revolutionary about the iPhone... I was already doing all of that while it was announced.
I think self hosting is in a similar spot right now. The apps exist (many are extremely nice!), the software exists, but the seamless, aesthetically pleasing and ergonomic experience does not. It's a pain in the ass to set up self hosting.