He’s a symbiotic monster who has a revenge boner, and even from his lethal protector days, there is just not enough here to work with to support multiple slates of films.
To create a cinematic universe, you need enough material to fill in, well, a universe.
The MCU, DCEU, MonsterVerse, and even the Transformers universe have more than enough characters and stories to provide a wealth of movies for years to come.
True, we don’t know who else will be in this Sony-verse helping to bear the load, but Venom by himself is certainly not enough.