Honestly I don't get why everyone's hating on Venom on here besides the notion that he's "too mainstream". Honestly Venom brings a lot more to the table than fan favorite Mysterio does.
Honestly, think like a writer and tell me- what does Mysterio represent thematically? How does he make Peter Parker grow as a character?
Venom is a man who's life was destroyed by Spider-Man, who wears the costume rejected and discarded by Peter Parker. He represents the demons he's created, the failures of his past, and the irresponsible choices he's made. He's a shadow that looms over Peter Parker and like any other personal baggage, he inhibits Peter from functioning until he is dealt with.
Mysterio on the other hand is a former stunt worker who uses illusions and tricks to commit crimes. Certainly there is something to be said about society due to his motivations coming from his attractive face keeping him from becoming a star himself, but he- as he is written doesn't do much to make Peter grow as a person or mirror him thematically at all.
I'm not saying I want Venom in the next film, but there's a reason the big three are Goblin, Ock, and Venom! So everyone needs to get off their high horse and stop trying to act like Venom isn't a good character.