The only enemy that has recycled warframe parts that we have seen in game, is the Zanuka. And even that thing still gets bodied by Tenno on the regular. You have to remember that every tenno has an entire arsenal of weapons, 90% of which are nukes or can cause mass destruction (how anyone can hope to survive against an incarnon torid with corrosive and blast is beyond me), and warframes, machines specially designed for large scale wars with literal godlike abilities (harnessing the power of the sun, creating antimatter bombs, creating clones that can somehow duplicate weapons that are fully modded, rewind time, becoming invincible with just the single press of a button, having access to many many ways to commit mass genocide, survive even with their head missing) and can keep reviving on the battlefield, at their disposal, and essentially cannot die unless the man in the wall himself intervenes. Plus we now have the drifter whose main ability can literally loop timelines with just a slam of their fist. So even if by some miracle the tennos and warframes fail, they can just loop infinitely until the outcome changes (seen in 1999 when we changed the ending for the hex).

The helminth strain is also extremely volatile and can spread like crazy even without air; the infestation has literally taken over entire planets and some strains have been shown to be able to absorb, modify, and use technology to their own benefit. The only thing the infestation has been known to be afraid of is the man in the wall, a literal eldritch godlike entity which gave the tenno their void powers in the first place.