The age of 33 still seems to be quite favorable for a short period of time. A good performance history certainly gets him good enough, but for injury history I think Napoli should be wary. They should be able to use De Bruyne well. His long injury history might come back if Napoli are not able to manage him. A 2-year contract is good enough to tie him down for the second year. I think Napoli can take advantage by reselling him. I think many MLS and Arab clubs want him.
This could benefit Napoli because Bruyne himself has quality and his presence in the squad will make the midfield better. The only problem that needs to be overcome is injury because this could be quite detrimental to Napoli if it happens because he is unable to contribute to the team. A two-year contract is enough for this player because after that Napoli can take advantage of sales to MLS or Saudi Arabian clubs so that the profits can be much greater.
But the most important thing is how Napoli can maintain their existence next season and come as Serie-A champions must be able to provide resistance. Bruyne is the type of midfielder who can pamper strikers and he has the quality to dominate the midfield so that it will make the attack line sharper with his presence.