Death is necessary for evolution. Shorter lifespans mean more rounds of genetic mutation meaning evolution can happen faster.

I think overall the point is right but I'd a lot of nuance.

- The evolutionary ideal lifespan for any creature is certainly limited but asking about the potential is more of a biochemical question and somewhat orthogonal to evolution.

- Some creatures fill extremely long lived niches proving that at the level of cellular dynamics, longevity is certainly possible.

- Humans no longer really depend on evolution. We'll start genetically modifying ourselves soon and I'd be surprised if there weren't any gm people walking around already.

- Our biggest limiting factor is experimentation. These experiments take a long time and aren't ethical to perform on humans. We'll certainly figure out how to make immortal rats before people.