They actually have opposite strategies - AWS and the other cloud providers charge a lot for outbound traffic to make it hard to leave them.
I don't know if edge computing really has the advantage Cloudflare wants it to have though; it reminds me of open source projects with a lot of mirrors thinking you'll carefully pick the one in the city nearest you, as if anyone even notices.
Having a ton of edges also give you the ability to do a lot more granular and faster DDoS/traffic load protection. You can, at its simplest form, just start dropping all incoming traffic to a destination at a node to save a site. With 10 or 20 POPs, that's a fairly big region. With thousands, it can get pretty targeted.
Every company claims to be worldwide, but when their site is down, they tend not to care so much if you just start nuking traffic from random foreign areas to come back up.
Not sure if Cloudflare does this today, but the potential is there.
