It's not that bad, technically speaking. It's quite watchable. It's just insulting to the viewer on many occasions, so that you're liable to end up hating it in spite of it being watchable and technically not bad.
It's not the worse film in the franchise, IMO, since it's definitely better than Alien vs. Predator 2. Now that's a legitimately awful film, not just because it's dumb, but because it's directed and acted poorly, has poor cinematography and effects and on and on. At least Prometheus and Covenant have good direction, cinematography and acting. They just have mediocre writing.
Technically, I'd say that Covenant is better than Resurrection, but at least Resurrection can be a little enjoyable if you shut your brain off. Alien vs. Predator is the same way. Even though they're not good, if you don't take them too seriously, you can still find some enjoyment in them. With Covenant, you can't shut off your brain because you're encouraged to use it to understand what's going on, which makes the failures of the writing stand out even more.