Actually, you're right. How would this work? Is Cloudflare really willing to foot the bill of 20 TB of bandwidth per day for a small text file that costs $0 to store?
Yes why not ? For reputation and attracting developers it seems to be worth it.
If it costs 75K USD/year, that's already paid back with one big enterprise customer only.
Though, adblocking is a big business, many actors there are getting large revenue.
For example, Eyeo's income was 50 million USD per year last time I checked (and I guess most of it is actually profit), so they can find a solution if they really want.
Egress is free but not public i.e. you can't just give anyone an url. You have to use your own server to fetch content from R2 and then serve it to your visitors. Each fetch costs money but first 10 mil reads are free and your own server probably has egress fees.
