> ...or have access to a licensed copy of the "real" Microsoft Office, the desktop app, which doesn't lag (that much), where all keyboard shortcuts work, drag-and-drop isn't too surprising, and you can use over a slow/metered/non-existent connection (bus, train, airplane), so you don't really care about Office 365.

Microsoft 365 allows you to download the desktop app versions of Office. No need for an internet connection after that.