[api]

Definitely Mac. They do telemetry, but three things:

(1) They do less of it, give you more control, and they do not seem to reset settings on upgrades.

(2) They have a history of actually standing up for customer privacy, and you are their customer. I trust them more in this area than Microsoft.

(3) I trust their security in general more than Microsoft.

If you want NO telemetry you pretty much have to run Linux and even there be somewhat careful about what you install.

[jdjd008]

When you say less of it, are there certain telemetry things that can’t be turned off? If so, which ones?

I tried Linux myself and it just wasn’t s polished product. Especially hiDPL, you get “normal” and “double”, that isn’t ok. Windows even gives you fractional options for that. I assume Mac does too?

[api]

Mac just hides DPI issues almost entirely. It's amazing. It's an area where Macs are by far the best, even significantly better than Windows.

You can disable most of Mac's telemetry in the privacy tab in the security settings, but I think it still will phone home for update checks and push notifications.

That being said I definitely trust Apple more than MS around security and privacy. MacOS also does not come by default with a bunch of crapware and ads. Last time I installed Windows 10 on a fresh machine for someone else it solidified in my mind that I would only use Mac or Linux, never Microsoft.