I get the strong feeling that, of course, MohinDUH! as Brundlefly is not going to be permanent. The whole business of him injecting himself with the serum and his behavior afterwards made me think of some guy who was high on drugs. Which makes sense because, after all, the serum is based on adrenaline from someone with powers, which could eventually disapate. And I think his "peeling skin" bit are a side-effect and the first sign that his powers are deterorating. In other words, his serum may depose powers to anyone, but only for a short time.
So I imagine that, in Future Peter's future where he talks about "powers, the greed, the war" is that normal people use this power booster serum to give them a quick fix, either as a recreational drug or for military applications, and the only way to make more of the serum is to extract it from people who naturally have the powers, hence Future Peter's comments about people like himself being hunted and forced to hide.