I recently had cause to rent a people-mover, and did so from two separate, off-airport local companies (not chains).
The 3 rentals all went off either a hitch, service was smooth, no wait, returns was trivial, cost was very reasonable.
It definitely showed me that if i need a specific vehicle for an edge case this is a very viable approach.
I don't see how you can have middlemen like rental companies take on the burden of peak fleet capacity for the whole economy, anymore than everyone can afford to own their own long-range ICE alongside a more limited BEV. It makes sense for some people, sure, but it seems like across the whole fleet we really need BEV to catch up and be suitable to cover these demands.
Otherwise, we need to address how those demands can be replaced with something else, like airplanes or trains, with more limited BEV rental at destinations. It seems disingenuous to me to suggest everyone can rent an ICE to cover the gap.