You’ve got a point. I’ve seen a Brazilian journalist talking about Neymar’s physical condition after this last injury, he did the math and Neymar was under injury treatment for more than 3 years during his career. To put it into perspective, Ronaldo was for 4 years. After the transfer to PSG the number of matches played decreased significantly. I think the answer is not gonna be a single factor one. Competing with Messi and C.Ronaldo, his professionalism or lack of, bad carrer decisions, injuries, timing, etc.
I’m Brazilian and out here, he’s never been an unanimity, both among journalists and the public, most because of his attitude, in the field and out. There’s a lot of things about his personal life that are talked about a lot here, that I don’t know if the rest of the world pays attention to, that helps painting the picture of how his personality might have influenced badly on his career.
I have a friend that had a knee injury playing football and had to undergo surgery. He started training his left foot since he was afraid to use his right leg where he had surgery. When he fully recovered he played mostly with his left foot.