The real story here is that Cloudflare is admitting to be a MITM attacker who is reading all of your private data going over the web.
https://blog.cloudflare.com/password-reuse-rampant-half-user-logins-compromised/
Password reuse is rampant: nearly half of observed user logins are compromised
Nearly half of observed login attempts across websites protected by Cloudflare involved leaked credentials. The pervasive issue of password reuse is enabling automated bot attacks and account takeovers on a massive scale.