Yes, well maybe in the future I will probably set up different build pipelines for Windows, Linux, mac os, ios, android etc... but then I would like to do it the right way with the right certificates and stuff. For now the focus is to make the game fun and balanced. I am doing very very small almost daily iterations and a complex building system could get in the way...
I know I am a year late but itch.io has its own app called itch which you can use to download any web games. I agree that learning a build pipeline just for your game to be available offline is a bit much. The only builds I can see making sense are for Android (or iOS too) because itch is a desktop app.