For small games/apps that usually have fixed window size for desktop mainly, I would create my own window frame and some interface elements themed for the game. If I make game that only need 800x800 resolution say that default window control frame just looks ugly
For windows I have been using Blend/Visual studio to create visual interfaces for small games, disabling default window frame.
When doing a manual export to PC/Mac, you get access to the code of the exported game. You should have a .Js file and a directory with the almost the same files as a local HTML export.
In the Js file (main.js), you should have this somewhere:
Yes, thank you, that will do magic, found the file in manual export, have not tried it yet but from my other project I know it will work.
Now I just wanted to add that I had a few projects where it has been mostly universal game design for web,smartphone and desktop with its own in game interface controls, and for desktop we had to disable window frame since it would duplicate the controls we created within game interface. That’s to answer “Why” with a more real example necessity rather than only for creativity and nice appeal.
Another example is that, when I was learning programming and interface design, teacher would disable windows frame (for windowsOS) and we had to ourselves create interface elements and make them interactable, so another reason could be “for the learning sake” since most people will design their own buttons any way
Also with removing window frame we some times had to make background layer transparent as well, which I have not noticed has such option for background layer (understandable tho). If you will consider implementing this as an option, then you might want to consider possibility for background layer to have opacity.