As it stands, that's true. However, with the continuous advancements in WebAssembly, and if we open a store where people can install open-source software, a lot of great things could come from that.
But... why not just let people install open source software as is? Stripping down the OS to "just" the browser leaves most of the OS. At that point we're arbitrarily restricting users to apps that run in the browser for no real reason or benefit.
I have not checked out any of this, but I guess the main advantage is that you can log in from anywhere, on any device that has a web browser, and have your full OS?