In fairness, hydrogen from gas would enable the CO2 to be sequestered. If the vehicle itself burned the natural gas that would require recapturing the CO2 from the atmosphere itself, which is much more challenging.

None of this is to detract from the attractiveness of battery vehicles.

Carbon sequestration is another of those "if we did this, it might solve the problem, but there's no serious move to do it and pay for it on the scale required, plus it's prone to cheating".