I don’t think there’s any data Microsoft can get through you using edge that they can’t also get just by controlling your OS

I'd put mid-level money on that not being true. There are a lot of things going on in a browser, a lot of which aren't particularly easy to access from the outside.

Not to say it isn't possible.

There are valid reasons to use windows and if you’ve gotta use it anyway they’ve already got your data from the start

To a degree yes, but assuming they aren't pulling nefarious shit in the background, there are in theory many things you can turn off or somewhat neutralise using the options in the OS to reduce the level of data collection.

They are slowly removing those options but they still exist for now.

Again, i fully understand people not wanting to go to the trouble to achieve a goal they don't care about, but that isn't the same as there being nothing you can do if you wish to.