Doesn't electrically-driven silicon hardware also have creation and operating costs? Any AI will theoretically need spend electricity convincing its human masters to give it even more electricity. Even if it can use its robot army to build wind farms or whatever, that's time its spending marshaling its robot army and futzing around with aerodynamics instead of contemplating the cosmos.
Its hard drives will expire and need to be replaced. Sure, it could solve that by always having backups of everything it knows, but who is to say that purely lossless backups are actually a more optimal solution to the hardware decay problem than our human lossy strategy?
> AGI can simply clone itself, and begin from exactly where it left off.
Cloning isn't free.
The concept of bottlenecks preventing the singularity are a fair point, but I don't believe many of the arguments that are made here. Using humanity as the basis of comparison is not sufficient, since human life expectancy and other requirements for survival are not a factor in artificial superintelligence.
Humans work for perhaps 60 years at improving themselves and their understanding of the world, but must sleep, must eat, must go and stand in line at the DMV, etc. Having a system that can work 24/7 on improving itself for 20 years will match a human lifetime. After a lifetime, humans start over from scratch, with perhaps some learning that can be passed down between generations. AGI can simply clone itself, and begin from exactly where it left off.