He used to be a great midfielder, but at the moment I doubt he can perform like he used to. Not being on the pitch for a long time can be a problem, even if it is not due to injury and he is still able to train, , but it's still not the same as if he was always on the pitch. So it is quite reasonable that no club has made an offer to him because that would be the same as making a speculation that could end in failure.
Paul Pogba's age might be another reason why some clubs are not interested in getting his signature. At 32, some players have lost form and are close to retirement. Some clubs wouldn't want to spend money on an unpredictable footballer.
If I were Pogba if there is no offer, I would play for any club for free. What he needs to do now is to assure clubs that he can still play top-class football. By playing free for a club, he would showcase his skills, which will attract clubs that will be willing to pay for his services. He is just like a new product that needs advertisement to convince customers to buy it.
He shouldn't consider financial benefits now, his focus should be to build the confidence clubs will have for him through his performance.