Gonna clarify a few things…

Hydrogen comes from water.

This is like saying flour comes from cake. You’ve got it backwards.

To turn an engine: We make controlled explosions inside a steel chamber to turn a crank using refined oil. The theory of operation does not change for hydrogen powered cars

Hydrogen opens up the possibility of using a fuel cell, skipping the noisy and inefficient combustion in favor of directly creating electricity and driving an electric motor.

Hydrogen: A truck pulls up to a beach - drop a hose - tank is full so wrap up the hose and drive off.

Not even close. To get hydrogen from water, you need a shit-ton of electricity and a lot of infrastructure, or you need to free it up with a chemical reaction (Aluminum and hydrochloric acid if I remember correctly). Right now the chemical way is lower cost and more available.

It’s better to use that electricity to move the car around, rather than split water with it and using the resulting hydrogen to move cars.