Different times, different people, different roles.
Ronaldinho was main man. Neymar is not.
Won the World Cup. Neymar hasn't.
Won leagues and CL with Barca. Neymar also.
Won the Ballon. Neymar hasn't.
Most important difference I think is Neymar has his dad with some good experience in organizing orgies, he'll get him all he needs at home thus no need to go out searching
Seriously though, I don't think the difference lies in sporting aspects, but Neymar's entourage being his family, and his father being the greedy agent he is, I'm convinced as I stated before that this will be what makes the difference and maintain neymar on the right rails.
In today's market and with his massive marketing potential, Ney Jr has all the stars lined up to end up with close to half a billion $ on his account just like Bekham did, his father won't let that slip away.