There's no reason 7zip can't be in the default right click menu other than laziness. Devs have had the option to add stuff to that menu since the start, but it wasn't until 2023 that they really started actually supporting it. Nanazip is 7zip with a Windows 11 UI and it supports the menu. https://lemmy.dbzer0.com/pictrs/image/388189f0-4926-4074-acbc-530f9596cc07.png