>That is not the open web that I would like to see.

Cloudflare is opt-in so I don't see that being an issue (yet).

Being opt-in doesn't negate the fact that it is closing the web.

I agree but it's a bit nuanced.

If you can still buy a domain, publish a site, and other people read it as usual, then the web is still open imo.

But I can see a lot of negative network effects if/when Cloudflare gets to control 60%+ of web traffic.

Internet walled gardens are all opt-in and still they've made the web a worse place.