Considering the barrier to entry for these rental companies to fast charge and/or renewables charge (solar?) on-site is far lower than becoming a gas station, I expect this to just be another axis they compete on as things mature.

That should translate into savings and/or warm fuzzies for customers in the long-run, though it may take a minute before we get there.

There was no realistic scenario for rental companies to start competing on this axis with ICEs, petrol is an inherently hazardous chemicals royal PITA.