This is my concern as well particularly, if the new Spider-man MCU films.
With the Raimi and Webb villains having been used in NWH , Venom, Carnage, Kraven, Chameleon, Rhino, and Morbius all being used in Sony's wacky Spin Off films, With the MCU already using Vulture and Mysterio, and with Kingpin off the table and Black Cat absent , I am concerned that the potential villain pool is getting thin in terms of threats that can compelling enough for a feature film.
Mr. Negative would be a great villain, but I don't know if Sony will allow Marvel Studios to use him.
There's always Hobgoblin , I suppose, and that could basically be the big bad for the MCU Spider-Man, but that presumes Sony will allow even that .
They're gonna do some version of the alien costume in the MCU ,and I suppose we'll get an MCU Venom, but even then , If it's Mac Gargan or some other character whose had the symbiote in the comics, I'm not sure how interesting that will be.
There are other villains like Hammerhead, The Jackal , and The Prowler , but Spider-Man all star villains have basically been done and probably won't be adapted again anytime soon.