Well it's definitely not as bad as Venom 2 (honestly not a difficult thing to do) and I've seen much worse in the last few years (like Rise of Skywalker). Jared Leto is actually pretty good in the role (the make-up for the disease is actually quite impressive). Matt Smith is very fun to look at (notably a scene where he dances). The powers are cool to look at as well (the echolocation and the shadowy-teleportation notably). And the music isn't that bad and honestly intense in some moments.
The rest goes from really bad to awful. The story is utterly cliché, Michael and Milo are the only real characters and everyone else is forgettable to the extreme (the two cops are just ridiculous, Martine is at best tolerable and Jarred Harris is wasted as ****), the fight scenes are bafflingly confusing (the final battle is simply impossible to understand and honestly gave me a headache), the motivation for Milo are not simply classic but barely developped at all, there's barely any blood in this vampire film (I didn't want a bloody thing like Vampyr for example, excellent game btw, but at least something more brutal and where blood isn't quickly put aside because we want our movie to be as safe as possible), the environments are forgettable to the extreme (squee, another grey city where it's night 18h per day, yay), the love story is really boring, just like many, many other scenes, and I would gladly talk about the editing if there actually was one in the movie (the first scenes and notably Michael and Martine in the lab are outright painful to watch and Michael getting arrested was purely hilarious for how stupid it was).
Oh, and the two post-credit scenes make no sense whatsoever with the MCU and are just bullshit.
Overall, not an absolute shit that destroyed my mind but it's definitely bad. Like really. 3,5/10 at best for me