The primary problem is that the web is client-server and there are substantial inconvenience obstacles to hosting your own server, compared to using a cloud service.
Then there is what Schneier calls the security feudalism problem: maintaining a secure system is very hard, so people prefer to submit to a corporate feu lord which can provide them with security, paying with their privacy as a form of feu duty.
> and there are substantial inconvenience obstacles to hosting your own server
I think one of the biggest problems is DNS.
Until there is an ubiquitous decentralized name resolution protocol there is not much of a point in running your own server on a host that changes IPs every now and then.
Dyndns has been a thing for years. It's not particularly hard to set up, but it's just another thing you need to configure. And I suppose it's an external dependancy.
Then there is what Schneier calls the security feudalism problem: maintaining a secure system is very hard, so people prefer to submit to a corporate feu lord which can provide them with security, paying with their privacy as a form of feu duty.