I'm interested to pick your brain about the second fundamental bottleneck you/the article mentioned. I'm not sure that I agree that serverless functions are fun

I'm interested to pick your brain about the second fundamental bottleneck you/the article mentioned. I'm not sure that I agree that serverless functions are fundamentally non-addressable. Today they're not addressable, but why can't they be in some future evolution of serverless? Sure serverless functions are ephemeral, but during their brief lifetime, is there something fundamental keeping them from being addressable?