It's a matter of time scales. If every car sold today were electric, it would still take 15-20 years for us to completely replace the fleet. Remember, there are a good 1.2 billion or so cars, and around 65-70 million are sold a year.
If the cost of this technology could be brought down within a decade, it would be a way of reducing emissions for the large chunk of the fleet that isn't electric, in a cost effective manner.
The other, more pragmatic, answer is that internal combustion engines aren't going anywhere. They have too many advantages over their competitors to ever fully go away, so we need cost effective ways of running them that are also carbon neutral or negative. Some of the links in this chain, like low cost electrolysis, are vital for other reasons (e.g. the food we grow uses fertilizer made from hydrogen split from fossil fuels. We need the fertilizer or the planet starves, and we need a source of hydrogen that doesn't also produce 11 tonnes of CO2 for every tonne of hydrogen produced).
If the cost of this technology could be brought down within a decade, it would be a way of reducing emissions for the large chunk of the fleet that isn't electric, in a cost effective manner.
The other, more pragmatic, answer is that internal combustion engines aren't going anywhere. They have too many advantages over their competitors to ever fully go away, so we need cost effective ways of running them that are also carbon neutral or negative. Some of the links in this chain, like low cost electrolysis, are vital for other reasons (e.g. the food we grow uses fertilizer made from hydrogen split from fossil fuels. We need the fertilizer or the planet starves, and we need a source of hydrogen that doesn't also produce 11 tonnes of CO2 for every tonne of hydrogen produced).