Centralization was absolutely the best answer to that problem and will be for a long time. Almost nobody but fortune 500 companies would be able to survive a DDoS otherwise.
> You don't solve a DDoS problem by having less capacity than your attacker and most individual companies can never afford the amount of bandwidth that is at Cloudflare's disposal.
You can have less capacity than Akamai (many excellent providers have less) and still serve this purpose.
1) are way more expensive than Cloudflare
2) suck at DDOS mitigation (there's a lot more to it than just bandwidth)
3) don't care much about DDOS mitigation (it is a side business from their actual business, which is edge caching)
4) drop customers who actually get hit with big DDOS attacks (see #3 above--they will always prioritize caching customers over DDOS customers)
EDIT- oh and I forgot to say that if your site is HTTPS, you will have to give Akamai your keys, just like you do with Cloudflare.