I honestly don't know if DeBruyne is a winning move, certainly the fact that he was injured for so long is not very good, you risk taking a broken player who doesn't even play a game for 2 years.
In this case, unfortunately, it's a matter of luck.
This is the only risk the Napoli club dares to take. because of course Napoli also knows De Bruyne's history of injuries. So this player is very prone to re-injury. So we also know the reason why Man City is not trying to extend De Bruyne's contract. And the reason is the same, namely that apart from this player, he is almost no longer young, besides that, it is because of his injury history.
But we all know that after Kevin De Bruyne recovered from injury, we could immediately see that De Bruyne's quality had not decreased drastically at all. In fact, he can still play very well and is still able to make a big contribution to his team. So even at Napoli I am quite sure that De Bruyne will be able to make a very big contribution.