Napoli is taking steps backwards. Ancelotti is not someone you build a project around. Sarri, for all his failings, had a clear style and future ahead of him for which you could invest in. You could take your money and what slight global appeal you've earned and used it to procure long-term options in the squad for Sarri.
The likes of Vidal, Di Maria and Ancelotti could flame out in months and no one would be surprised. Certainly none are long-term options. It seems like a big waste of such momentum.
If everything clicks just absolutely right, then sure, they have a bigger chance next year. But the margins are razor thin and after next year, it could drop off really quickly.