Bale and Hazard are talented players. Real Madrid made no mistake in bringing them to the team. If their fitness problems could be fixed then we would get proof of their ability. Neymar also has a lot of fitness problems. PSG paid him a lot of high salaries, but Neymar could not play for almost half the season due to injury.
But Neymar is still different. He is not that prone to injuries as Bale and Hazard. When Neymar played for Barcelona he hardly missed any games. Bale also has motivational issues. Just recall that he played gold alone when the team met to have a team barbecue or other team building events. It often looked like he is an isolated part of the team, but he did play well. The goals he scored in the champions league or in the copa del rey final against Barcelona were just amazing.
I agree with you. Neymar is still different. He suffered fewer injuries when he played for Barcelona. He had outstanding performances with Messi and Suarez. But at PSG he has suffered a lot of injuries. He has been at PSG for 4 years. Neymar has played only 70 out of around 150 matches in 4 seasons. He has played in less than half of the matches. Hazard, on the other hand, has played 30 matches for Real Madrid in two years. However, we must remember that the salaries of Neymar and Hazard are not equal. Neymar's salary is too high.
Considering the salary aspect, since Neymar's salary is slightly lower than Messi and Ronaldo, we should compare Neymar with Messi and Ronaldo. After spending so much money, no club would want their players to be injured so much and out of the field on important matches. Messi and Ronaldo play more than 30 matches each season, but Neymar is unable to play in 20 matches due to injury.