Half of Ronaldo's career games have involved him doing very little then assisting or scoring a goal. And he is considered one of the best players to ever live because of the incredible end product he brings. KDB is similar, he is not a 90 minute 'presence' like Silva who runs the game himself, but has an incredible impact so doesn't need to make 100 passes or anything like that. So you can't judge KDB by that criteria or else you're putting down some really good players.
I agree with Dax that no player in the post-takeover era has debuted with such an impact as KDB. It doesn't make him better than Silva or Aguero (time will tell), but the signs are good. If he maintains this level, he will continue to be (as he was last season in the BuLi) one of the most productive players on the planet and considered as one of the world's best. And IMO, he is the sort of player who can and it looks like already is helping us a lot in Europe where our revered spine has not been as effective as they have domestically in 4 attempts at going far in the competition. I think 2014-15 De Bruyne is better than Gareth Bale in the same timeframe and is the sort of player who will scare teams in Europe because he can come up with an end product at any moment.