Comment by johnhess
7 hours ago
This separates who sees what. Cloudflare (or any OHTTP gateway) sees who talks to who, but can't see the content. The service sees the content but not who you are/your IP.
You can imagine a lot of threat models where who you talk to isn't sensitive, nor is "someone talked to them about X" but knowing both facts is a risk.
For a single transaction that's great. The problem is whene a large fraction of the internet is served by a single entity (say cloudflare), then that entity has information about what sites/customers were visited by a specific ip address, and which ip addresses visited a certain site/customer.
Although, that is still better than them having the source ip and the content.