The situation of Neymar different from those two big stars. Since both are healthy, while in Neymar case he's currently in recovery mode. There's nothing to look forward that he can play on highest level, since as what we discussed he's recovering from his injury.
Neymar has returned to training with Brazil and he looks so bright and confident. But that doesn't mean that he might not get injured just in the next match day.
Media just pressure and I think trying to hype him on the squad, but that disturbance they made cannot change the fact that his injured and not in his best shape.
Neymar is not in his best shape just like Ronaldo who is also affected by age. But there's this aura these big names bring to the game
Also we can see on Brazil's case that even if they have the strongest roster, this will not convert to automatic win. Yeah they have those talent that they need, but what they need is chemistry and also consistency. The unavailability of Neymar gives lots of problem to them.
Brazil recently no longer has that smooth take off in tournaments.
I also agree with you that Neymar's presence could bring the lacking chemistry amongst the players.