Then why do they offer a separate, distinct DDoS mitigation feature on the enterprise plans? And did you notice they call them “mitigation” and not “protection”? 🙂
Look at the description of each one, the free one “stops illegitimate traffic at the edge”. Meaning they’ll serve from cache, it’s not getting through to your actual site. You can get caching from any CDN service, it doesn’t have to be CF. All CDN services are distributed and will try to serve for as long as possible because their whole purpose is to deal with traffic spikes.
And if you want to know for how long CF (or any service) will serve from cache and how far they’ll go for an account (especially a free account), you want to check the terms of service not the plans. The plans are made to sell to you, the fine print is in the terms.
Anyway, I really don’t understand people’s obsession with DDoS, particularly self-hosting people. The chances of their little website ever being the target of a DDoS are astronomical. Many of them don’t take proper backups, and don’t worry about theft or fire or electric spikes, which are far more likely, but go frantic when they hear about features they’ll never use.