The thing is most companies would want to have a web presence anyway. It's just easiest exposure and people have to be willing to install a software - visiting a website not so much.
So if you're building these cross-platform apps on anything other than the Web stack people will still have to have different code bases for native and web which kinda defeats their purpose.
So I don't think you have any real alternatives until there's other technologies on the web or wasm can do everything.