Hosting large datasets can be expensive but the hosting for the danbooru datasets was not.
It's "only" a few terabytes in size. A previous release was 3.4TB, so the latest is probably some hundreds of GB, to a TB~, in size larger.
The download was hosted on a hetzner IP, which is a provider known for cheap servers. You can pay them $50/m for a server with "unmetered" 1gigabit up/down network + 16TB of disks.
$600 a year would not be difficult.
Cloudflare does allow R2 (& some other "Developer Platform" services) for non-HTML content. They made some TOS changes in the past to be more explicit about it.
Windows had an ICMP CVE last year and also just released a patch for an IPv6 CVE. OpenSSH on Linux had a CVE recently too. Security in depth is reasonable and not baseless.
Probably about the protocol being more complex with less implementations or the forced encryption which means acquiring certificates for TLS. Spoofed IPs for DDoS is a bit more troublesome for UDP protocols, though smaller players will get smacked down by any DDoS anyway. I hope to see more applications and games wrap their traffic in QUIC/HTTP3 to "defeat" firewall filtering.
A lot of english-advertising hosts from the regions in my comment are going to advertise DMCA-ignore, freedom of speech, and/or privacy. And you basically can't go wrong with any of them. Seedbox-as-a-service providers specifically are going to be generally be fine too although many of those are hosted in Netherlands which is slowly becoming less copyright-infringement -friendly.
One specific host I'll mention is vsys.host (UA) (which anna's archive uses too) but they're not going to be the cheapest option.
I'm not looking to buy property but I wanted to let you know that it seems hard to look you up. You don't have an email or name on your profile and the username isn't very unique online.
https://bugzilla.gnome.org/show_bug.cgi?id=758032
https://github.com/linuxmint/cinnamon-screensaver/issues/354