When I've looked at the power and energy requirements of vehicles it seems to follow some sort of log(size) law when it comes to speed and energy per mass distance. But not for acceleration which is linear.

What that means is a small vehicle like a motorcycle needs more energy and hp per lb than a car to have the same range.

So could see higher performance batteries being very useful for motorcycles. Have heard noises that electric motorcycles and bicycles are heavy feeling. So lighter probably would be considered better.

A guess: existing charging infrastructure is too slow/low power to charge this fast enough to be useful over currently standard batteries for car sized batteries

It can be many things, like large car companies staying away from unproven tech or them demanding production capacities too large to gamble with brand new tech.

This niche motorcycle brand has already established business relationships with Donut Lab, they were using Donut Lab's electric motors. Probably the Donut people easily worked out a release pipeline together in a bar or something, which would have taken years with VW.

I would assume it’s a capacity/scaling thing, plus bizdev. Car companies source things on much longer timescales and build many many more units.

Owners are the same