There are only a couple of scenes in this movie that could be considered B movie shitty. The rest is just horrifically bad.
Adding Wesley Snipes in a typical badass role is useful if only the majority of the scenes he's in would have made sense. Unfortunately it's worse than 'that bad'. It's just random shit happening to fill the empty minutes between the start a couple scene that explain the movie and end.
Having watched the whole thing though.. sure the concept is something that's been discussed before in sci-fi, at least the recall tries to put it into practice. But the stupidity of the movie's story and horrific visuals and acting ends up wasting a great opportunity to explain why aliens would come to earth, find candidates, take them, provide genetic updates and then show what those candidates would do with those upgrades.
Being randomly chosen to be better faster stronger doesn't mean those 20k taken that were returned will survive any better and end up spreading their genetic upgrades with other humans. Eventually some of them would breed but the conflict the movie sets up doesn't make it seem likely. But at least 20k people breeding with each other would be capable of building a great population given enough time alone. It would explain why the aliens took hot young people. Getting the smart ones would also be challenging so I'm guessing the gross majority would not be 'smart'.
At least the idea of studying humanity (and any really successful animals with traits we haven't developed ourselves) and fiddling with our genetics to create those upgrades makes perfect sense. On the believability side there's the part where it's impractical for aliens to travel all the way here to keep tweaking the genetics of monkeys. Hell they might even be annoyed with the deterioration of the environment of their lab. Adding some extra traits for survivability in a progressively polluted world most likely.
And those are really standard looking aliens (based on grays). What point is there editing our DNA unless it benefits them? They aren't portrayed to be needing anything they are adding to us. Had they said like ok 2 billion were taken as slave workers ok. 20k were tweaked and are expected to dominate the remaining 5 billion then ok maybe. At least their slave population would be even stronger for the next time they come back. But if they are that much stronger what's to stop them from killing themselves off? We've been at the brink of annihilation for a while because we are so clever.
Making humanity stronger physically and mentally and expecting them to compete could lead to a really short conflict then protracted peace where populations would balloon again to tend of billions to hundreds. Which would be great right now since we need a work force to build space ships and fly them out to new worlds ourselves. Right now would be a really great time to have that kind of intervention happen.
I'd only hope that it wouldn't turn into a The Expanse future where only a few people benefit while hundreds of billions live in squalor. That 'some things never change' bullshit annoys me. Upgrading people only to have them continue to scrape by. But I mean it would still take many generations for 20k people with tweaked genetics to breed those advantages into the whole population. Even as a cool thought experiment, like considering how mobile the more advantaged people are... How long would it take for their genes to appear in everyone? Just consider that's is been centuries since the largest empires started setting up colonies. After a few generations of genetically compatible cross breeding we are seeing some advantages but also high rates of cancers asthma digestive and other degenerative issues. Why not more benefits?
If the aliens altered our genetics too much they might no longer be compatible with the older humans. The first few cross breeds might be horrific failures. Monsters even.