Except that it is not. The security and constant maintenance is needed but it is worth in many cases. And large companies can not really off load all ownership of data and applications. The interest in servers actually went in reverse direction due to the cloud effect.
I would say having own server or application hosting capacity is very similar to why you produce your own solar power and store it in batteries - it is simple? No. But the technology is improving and thus it makes it easier for people to adopt this paradigm.
When I see what is happening with WebAssembly/WASI in particular, I see a great future for self-hosting again. Software written in any programming language (as long as it targets WASM) is a lot easier to host than existing models. Also there is interoperability of software coming from different languages at the WebAssemply level as I understand.