Beckham isn't exactly your typical winger, sure he delivers good crosses but he rarely beats his marker. I think Beckham play wide but he's no winger. He can play as a winger in a 4-4-2 but he would be absolutely useless in a 4-3-3. All other top wingers can play in it, Camo, Di Natale, Ronaldo etc...
I think Camo is rather fast actually. Not too many players can outrun him.
No matter how good you are technically, if you lack speed, you can't play as a winger. That's why players like Riquelme, Totti, and Del piero can't play as wingers. While you see players like Di Natale who isn't as technical as any of them but is faster than any of them perform superbly on the wings.
Another point is that wingers are often used for counterattacks. Hence, the 4-3-3 formation. It's a counterattacking formation and if the wingers aren't fast enough, it's pretty much useless. It's really a lot about pace, that's why you never see old players playing on the wing. You would naturally see younger players on the wings because of the mountainous amounts of running and quickness the wing position needs.