That's the issue; hydrogen has none of the inertia of fossil fuel ICE, most of the drawbacks, and a ton of its own unique issues (like bulky/dangerous storage of hydrogen). It won't be cheaper than ICE. It won't be cheaper than EV-drivetrain hybrids, either.

And even if hydrogen cars were somehow cheaper, why spend billions setting up hydrogen infrastructure? We already have gasoline. Or natural gas fuel cells, if that's the tech angle.

Hydrogen was an interesting "transition" fuel like two decades ago when electric drivetrains and power transmission were less advanced, and leaders thought populations would care about climate change. But society collectively decided to just ignore it and keep using gas. Hence I think that window is passed.