I think the people who found this show bad perhaps had the wrong expectations. This show isn't canon, it's just an excuse for various animation studios and directors to make their own spin based on the rules of The Boys universe.
My favourite episodes were episode 2, 4, 7 and 8. I enjoyed Justin Roiland's sense of humor, so I liked seeing what he did with the concept. The romance in episode 4 was cute, albeit a little underdeveloped (which is excusable given the short runtime), the animation of 7 was by far the best, and 8 was a mini flashback story for Homelander that makes his character a little more empathetic.
Most people have an issue with episode 5, the poop episode. The animation was cute, but I think Awkwafina was high when she wrote the episode. Even with the absurdity of the Boys universe, the premise of episode 5 was a bit too crazy. I wouldn't call it bad, but it is the weakest episode.
Episode 1 was just a Looney Tunes spoof which went a little too hard on the violence for its own good. Episode 3 was really fun, and uses the character designs of the original comic instead of the TV show. Episode 6 was good but barely felt like The Boys at all, closer in tone to Invincible.
Overall a mixed bag, but I lean more positive than other critics here. Worth watching if you need more Boys, and don't mind an anthology series.