> one of the nice patterns of cloud hosting is how application and data servers are hosted behind firewalls of some kind

Oh I see, so that I benefit from the "professional" firewall of Cloudflare, as opposed to my own that I may have possibly misconfigured or forgot to update etc?

Or is there more, like Cloudflare will block IPs that know to come from malicious actors and things like this?

Both are a yes.