That surely is only because there has never been any real incentive for the ICE designers to do anything else. No legal or governmental pressure has been applied to them. Governments have been perfectly happy to keep taking the massive taxation that has been applied to oil and as long as the money was rolling in, why would they wish to disrupt it. The only real times the ICE designers ever really made great strides in the engine performance has been in F1 and at times when there has been an oil crisis which forced them to look at increasing economies.
I suspect that big oil has invested very heavily in the EV side of things, especially on the battery side of things as they can see the opportunity to make billions with far fewer people involved, therefore even greater profits, no oil refineries, no great oil tankers required, maybe easier extraction of the required minerals, follow the money. It is all to easy to swallow the stuff we are all being told about the EV being a magic bullet and the answer to the planet's problems, but is it?
If we all had to live with the mines used for extraction of the rare minerals for the batteries and all the toxic waste and poisoned water supplies as result of the toxic lakes, the hazardous living conditions that people in those areas have to endure, the poverty, poor wages paid to the workers, even young children etc, would we still think that the EV's were a good thing?
These are the side effects of EV's that we and most people do not get to see or have to put up with all we ever get to see are the good side of things and is this not just really a massive case NIMBY syndrome??
Man created the climate change, man could also reverse the change, but the problem there is of course no commercial gain to be had from doing so, once again we are back to the money. Even if there were zero toxins coming from the adoption of EV's, it will not cure the climate change, it will still be there.
What we need to do as a planet is to restore the forests, make the planet as a whole far greener with actual growing plants, that will convert CO2 into oxygen. Also develop processes that actually take CO2 out of the atmosphere and restore the ozone layer, yes it would cost money and nobody would be able to make a profit from such actions, but we need to stop the relentless pursuit of amassing as much wealth as it is possible and locking it away in various tax heavens that the top few elites love to do. Maybe if they had paid their fair share of taxes over the years, their taxes could have been used for the purposes of tackling reversing the damage we as a species has done.