I have to say that whole outlook isn’t as good as gmail, all the things evolving spam is super easy to handle with policies. I still have my old gmail address forwarding things that google would sort into “this is the relevant mails” part of its new inbox system, and 90% of it goes directly into my “unwanted stuff” or clutter or whatever it’s called in outlook.
As a benefit it also gave me a TB of storage and in browser office, and while I don’t use the office stuff much, I do use one drive to backup my photos because iCloud storage frankly is almost as expensive as the entire office365 account.
There are providers that directly exploit their graph by selling the PII within it, such as GetEmails[2] (and the publishers they source data from). But Google isn't one of them.
[1] https://developers.google.com/ads-data-hub
[2] https://martech.zone/getemails-identify-anonymous-visitors/