There is no install needed, you can just edit permissions and make the file executable and then when you open it or click it the app runs.
What won’t be created by default is an application menu to run it from whatever desktop environment you use. You can create those if you wish. You can create a launcher in the menu manually, or you can use a tool called AppImageLauncher to create these for you.
There’s a pretty good explanation here: https://askubuntu.com/questions/1311600/add-an-appimage-application-to-the-top-menu-bar
I always heard it as intelligence tells us tomatoes are fruit, wisdom tells us not to use it in a fruit salad.