Power delivery. If both the charger and device implement it according to the spec they indeed negotiate the voltage and amperage they will deliver. However not all chargers (properly) implement the spec

Fire wasn’t invented back then

It can detect cycles. From a quick look at the demo of this tool it (slowly) generates some garbage text after which it places 10 random links. Each of these links loops to a newly generated page. Thus although generating the same link twice will surely happen. The change that all 10 of the links have already been generated before is small