I agree with you that it is not about having the best players but having the right players to yield to good result at the end of the day with a good coach matters a lot.
A team might have quality players both still gind it difficult to become successful at the end of the competition and a team with few good players might end up winning the world cup. However, a good team needs good players to become successful.
Brazil's situation is complicated. I can't deny that in the last few games we haven't seen an imposing Basil, like he was some time ago, when they were winning almost from the first moment, almost from the first 5 minutes the teams ended up cornered. I think the perfect solution is a new coach, because they haven't been good at how to do things. They have very good players, but they limit them, or they make them play a type of Football that they don't know how to play For example , the team doesn't know how to play defensively Brazil's best defense is its attack.