I think this will really make it difficult for him to achieve the achievements he has now when he returns. Building a career in the world of football is very difficult and requires a long period of training and hard work. And with just one mistake a soccer athlete's career can be ruined. I personally still hope the best for Pogba. However, he is a talented player on the field. He is already 30 years old, but that should be his peak age to show all his prowess on the field. I think Juventus really always has problems every year. Whether it's from an internal or external perspective.
We can say that his international football career is over, he may still play after serving his sentence but perhaps we will no longer see him playing for the French national team and also playing for one of the big clubs in Europe, not only because his performances will no longer be impressive but his frequent injuries would prevent any elite club from making him a player. You are right, it seems that every season Juventus faces a lot of problems, bad management and now their players are exposed to doping cases, but we also see that they can always get out of the problem.