While there's no fixed criteria all comic book films have to meet, it makes sense to depict certain types of characters in a fun light. Venom might not necessarily look like one of those characters, but he's still a product of the nineties, a decade in which Marvel quite literally did not care.
Everything about Venom's design harkens back to a time where Todd McFarlane and Rob Liefeld reigned supreme, and while that's not a bad thing per se, back when the pair were prominent Marvel creators, the focus was less on nuance and subtlety, and more on high-concept artwork and dark storytelling. Spider-Man's darker, less conventional storylines during McFarlane's reign felt particularly contrived, but there's a kind of enjoyable irreverence to it, much like Venom's OG comics themselves.
At the end of the day, Eddie Brock is a product of that decade. He's been elevated through subsequent storylines and by writers not of that earlier milieu, but everything about the character, from his name to his design, is of a time that valued style over substance. Venom today boasts both in spades, but there should be something in the film that appeals to the character's OG fans.
And it will, supposedly. While the film will be a horror, it's also said to have plenty of "pop and fun". Yippee.