So what should I do if I want to make an app with this functionality? Do I have to tell users to download and run some executable? You can imagine a case where that is a bit riskier than a nicely sandboxed web app with permission to access one directory.
Just because a problem is not hard to imagine it doesn't mean that the problem is actually a problem in practice. It is worth asking if there are any signs of it existing for real.
I hear a lot of this "nothing has happened so far" from people who DUI before their first crash and people who use the same password on multiple sites before their first credential stuffing hack