Orcs, to me have a simple hook. They're the ravaging horde seeking destruction of the civilized races which they think are weak. I don't need or want much more than that. They're a genetically engineered race made (and controlled) by a vengeful god; if they were real I'd actually feel sorry for them.
There are three problems which you're not really acknowledging with this:
1) They're not consistently presented as genetically-engineered killing machines who are sort of the "dead hand" of a vengeful god. In fact, that's quite a rare presentation of Orcs. Typically they're presented as "a tribal race who are strong and violent, and worship a nasty god", which is a very different kettle of fish.
2) They have, including in 5E, aligned perfectly with some really SUPER RACIST tropes that been put around about black people and asian people at various points in the 20th century. Now, that's not your fault, and arguably, in some early iterations, they didn't align as well with these SUPER RACIST (like whoa) tropes that have done at other points. But all the stuff about them being fast-breeding, unnaturally strong, brainless violent thuggish worshippers of darkness who descend as hordes to wipe out "better" races is basically literally straight up the text of racist history books, propaganda articles and so on. And not in like, the distant past. Like, there are Facebook posts right now, this second, still saying this kind of thing. There were textbooks saying it published within MY lifetime, and I'm only 42. Some people playing D&D read those textbooks (I'm not saying they believed them or whatever, but point is, the contemporaneous).
EDIT - Hell, there are Bush-era textbooks which had tame versions of this stuff in them (but the same essential sentiment). Fringe textbooks, but ones that got into schools in parts of the US. I'm not even going to start on some of the more recent stuff of a similar nature.
3) It's too late to revert to "Grummsh's GEKMs" as the only trope for Orcs. We've had decades of other presentations being the majority presentations - primarily the "violent tribal people" presentation.
I think you're coming at this like, could you have a race which was just genetically-engineered killing machines who are sort of the "dead hand" of a vengeful god and it not be problematic? Yes. But you'd want to do stuff like have them coming out of sludge pits like LotR, or be manufactured by some ghastly machine (surprised Tolkien didn't come up with that actually, seems like he'd have been into it), not be flesh and blood creatures with opinions and free will, which they explicitly are, even, unfortunately, in the "Grummsh's GEKMs" scenario. They should have NOT had free will. They should have been made in pits. They shouldn't have been extremely well-aligned with ultra-racist tropes.
It has to be fixed now. And the fix means de-aligning them from ultra-racist tropes.
By all means create something that fills the same role as you're proposing, or even use Orcs - but I hope you can understand why they're no longer suitable for this role. TSR and WotC screwed up. They created this situation.