Cloudflare will disconnect you from their free plan just as quickly.

Especially when you are facing "infected machines by the millions".

Likely true, but now you can go back to the original statement: the issue isn't really that the service isn't available for a while... It's that the hoster will remove your server.

Your server will keep existing if cloudflare just drops their free service, effectively going down for the ddosrs but still available for your own access directly

Citation needed. I know folks using the free plan that have gotten ddos’d and cloudflare kept them online. Can you point me to an article where cloudflare disconnected someone for getting attacked

Except that Cloudflare is geared towards ddos protection - i.e. you can monitor, get alerts, turn on temporary protection, etc. It can do this because that's it's main business. It's not possible to have the same expectations from infra providers like Hetzner.