We can't compare Pele, Ronaldinho, Ronaldo, or other similar players with Neymar, they played for their national teams for a long time and they earn many achievements also compared to Neymar these players had much better performance and they had more stability while a player like Neymar can't have weeks of good performance and then just like this year, he can disappoint while the team.
I think the generation of golden players in Brazil is over and that's why they couldn't earn many achievements recently in the world cup.
A few decades back, teams like Brazil and Argentina were ahead of the other teams in terms of quality of play. But this gap has disappeared now. Also, the local leagues in these countries are not of high quality and therefore the players opt to play for European leagues. This is having an impact on team bonding, as nowadays the players remain with their club for almost the entire year. International matches are given a low priority when compared to club matches and even while participating in national matches the players are very cautious to avoid any injuries.