I think you’re right, hydrogen is ludicrous, and bang for buck, some other tech will win out for time shifting the power, probably pumped hydro.

edit to add: Hydrogen is ludicrous in the primary context of a battery. There’s other potential uses such as making steel, making ammonia/fertilizer etc that could change the equation again. Hell, you might even find it desirable to make it HERE and transport it THERE as a battery, but again, the maths are currently wrong.