You do understand that Rugby 7's is to proper Rugby, what the Arena League is to the NFL.
The best Rugby players in the world don't play sevens.
Currently we are in the middle of the Six Nations which includes England, Scotland, Ireland, Wales, France & Italy, and they all have their best players playing in that tournament.
Even the next level of players are not playing sevens, they will be playing for their club sides.
I'm sure that if the All Blacks diverted their best talent from the 15 man game to Sevens, they would have the ability to beat all comers