I'd actually love a subscription that covers multiple low-traffic domains.

Next to a few business accounts for larger projects, I probably have 30 low traffic sites which aren't much of a cost for Cloudflare. I'd happily throw something like 20$ per month their way to have them covered.

I'd happily pay $5/month if it covered all of my hobby projects.

I'm not interesting in paying to run just a single project.

I'd be the same as you. All of my hobby sites combined probably get 1,500 views a month. I'd happily pay the $5 to cover that.