A popular use case for SaaS companies isn't even in utilizing Zapier themselves, but rather adding their API to the list of integrations. This can really speed up onboarding for customers -- especially if they already use Zapier.
In order to charge 10x faster, you need to deliver 10x the current. That means all the wiring and electronics need to be upgraded to handle the huge increase without melting.
Also, the rest stop won't just be installing a single fast charger, it would install more than one. So you can't really compare 10 slow chargers against a single fast one. That means the wiring service for the entire rest stop would likely need to be upgraded as well.