It makes a lot of sense from technology, environmental and maintenance standpoints, but unless they can get the price and charging speed down significantly then fleet owners will continue to choose gasoline vehicles.

Swappable batteries, like they have for electric warehouse forklifts, would likely help solve the charging speed issue... but it adds an infrastructure challenge. Someone like the Postal Service would be a good candidate since they have many "warehouses" where they could station battery chargers/swappers. AMZL, UPS, Fedex, etc would be more difficult since they tend to have fewer warehouses that are further from many of their delivery endpoints. It's not impossible, and they'll likely be forced to go electric at some point, but it will require additional infrastructure.