There’s every reason why hydrogen powered cars are not practical and are unlikely ever to be, until and unless hydrogen is capable of being produced using cheap electricity.
Ther is green Hydrogen that has started to be cheaply produced and will no doubt be developed further and nodoubt will be reserved for HGV’s and heavy machinery.
It will be interesting to see what is done with aviation considering EV’s loose alot of range at at 0c let alone -50 odd c!