Yeah Microsoft Rewards is super annoying, and I'm not sure who even actually engages with it. But if you want to use windows you can remove MS rewards from your account and the notifications stop [1].
IMO "you can turn that off" is absolutely not an acceptable answer to this stuff. It's my computer and it shouldn't be doing anything that I didn't specifically tell it to do. And that's not even to mention how often these setting are reset, or new "settings" added
https://promos.microsoftrewards.com/US/en/SS/88/rules
Edit: Chrome isn’t even installed, I use Firefox.