Office is another such item I would gladly omit from my Windows OS... its a commercial tool and like you say opts in on other services and before you know it, you're stuck with the whole shebang. There is OpenOffice...
Luckily I still have an Office XP Pro...

Still works a charm, does everything it needs to... and
stays identical. Also no ribbons. Aaahhhhh glorious. Although I gotta say the ribbons are something to get used to, and when you do, they're okay, ish.
Yep... technically I trust the cloud... But technical perspective isn't reality and certainly not security.