Why Apple is not Tor
"When browsing with Safari, Private Relay ensures all traffic leaving a user’s device is encrypted, so no one between the user and the website they are visiting can access and read it, not even Apple or the user’s network provider."
About that. The user's ISP is cut off this interaction, but the rest of that's likely wrong or definitely wrong. The feature supposedly integrates with Safari. Unless that's just a brand name for a disconnected feature, there's a good chance that the only traffic which goes through the system is traffic generated by Safari. That is the important stuff if you're worried about people stealing or compromising your data, but it isn't all of it. The rest of it includes plenty that can be used to fingerprint you. That can help to reassociate your traffic with your device if the attacker is sufficiently motivated.
The more important part is the suggestion that Apple can't associate your traffic. It's complete rubbish. They can do so by comparing logs of traffic usage. Such techniques are used for Tor already, and they work there too, but they're not reliable when used there. The reason: in order for it to work, the attacker must operate all the relays in use and Tor is made up of a bunch of independent relays so you have to spend a lot and hope that the random path generator has put the victim in your sights. Apple's system doesn't use independent relays. They operate every one of them. They can easily use attacks like this if for some reason they decide to. That is without considering that they could just log while forwarding your connection from relay 1 to relay 2. It's not using an open source protocol, so we can't confirm that they're not.
This is not a Tor-style privacy protection. This is an Apple VPN. It's probably fine as a VPN, and if that's all you need, it's probably safe to use. Just don't expect more from it.