FWIW, my 2007 Camry hybrid died last year with no warning. car still ran fine as I was driving back and forth from FL to Pittsburgh, 1,000 miles each way. You would think if the Prius had a limp mode built in to make people buy a $3,000 replacement unit, they would do the same on the Camry. The problem is the cruise control was disabled during those long trips back and forth. Never realized how much I used CC until I couldn’t move my foot for a few minutes every so often. $1,600 for a new battery and all is good at 250,000 miles.
I am not sure but I think each fleet finds its own way to manage total energy output mandates.