That’s irrelevant. This proposal only gets bad if enough browsers support it that site owners can tell everybody who doesn’t use it to leave. At that point the open web is dead.

This thing is a security nightmare. Websites that implement it will likely come to regret it.

It has nothing to do with integrity and everything to do with them forcing content upon you which you have explicitly chosen to exclude. Additionally , this will likely be the final nail in the coffin for small webmasters. You won’t be able to spin up a little passion project anymore and have it visible by the rest of the world unless you understand the complex requirements for implementing the new system. Mandatory SSL already hurt a bunch of small businesses and bloggers, and that was relatively easy to solve if you threw more money at the problem. This would kill the open internet.

Apple put it into their browser but Cloudflare is heavily involved in the standard.