Same thing that's wrong with oatmeal: Nothing, that's just not what it's for.

Github and tools like it are designed for codebase versioning. It's a great tool for developers who have a need to collaborate with others and manage releases/branches. But, it's really not great for distributing executable apps to end users because it's not for that. You shouldn't tell end users to clone a git repo and type make install, because that's not normally how people manage software.

If possible, the app should be packaged and in a software repository/app store typical of the platform. Chocalatey on Windows (Microsoft has their own Windows Store, but fuck that), Brew on MacOS...if we're talking about an end-user application for Linux, I'd recommend Flatpak because it's become the de facto one to rule them all; if you really must host something on your own website right next to a windows .exe I will say go with appimage.

You can get hosting for distributing end user apps, Github has a service called Github Pages for this purpose, for example. But especially in the Linux world, too many creators of little things like to just point you at their git repo and only accept user feedback in the form of pull requests.