The biggest argument against interoperability is speed of change. Telsa, the leader in electric vehicles, makes a lot of their own components and algorithms. Standardization in fast moving areas slows down the pace of change. We are at the dawning of the electric car age and even earlier in the self-driving car age.
Standards tend to either work well with mature areas or in areas where people need to pool resources together either for money or legal reasons (see codec standards).