Yep. Set up Charles Proxy (GUI) or mitmproxy (CLI) if you want to take a look at the actual data. It's huge and non-stop. Some of this even Little Snitch can't

Yep. Set up Charles Proxy (GUI) or mitmproxy (CLI) if you want to take a look at the actual data. It's huge and non-stop. Some of this even Little Snitch can't stop because it's sent to random IPs inside huge blocks belonging to Apple with no DNS. Unless you go to extraordinary lengths it's the same with Firefox FYI. These companies' privacy concerns are a marketing gimmick, and the situation is so out of control we have to be thankful even for those crumbs.