My understanding so far is that you can run an application in the browser. It is neither a web app nor native app, but a WASM app.
People speculate and their erroneous speculation spreads.
Saying executable files implies erroneously that applications built for desktop execution can be executed in the browser. See WebAssembly. It says WebAssembly (abbreviated Wasm ) is a binary instruction format for a stack-based virtual machine. And it says WebAssembly describes a memory-safe, sandboxed execution environment.
Also see WebAssembly | MDN. It has many instances of code being compiled to WebAssembly. Use of WebAssembly requires use of a compiler that generates it, unless a programmer writes WebAssembly directly.