As VED bands are organised so that it is cheaper for more fuel efficient cars, there seems to be absolutely no reason why there can't be a VED element to the tax on fuel.
Try evading that.
I suppose there would no longer be jobs for people tasked with creating hopeless online services that conk out at the first sign of load; or for those who make money flogging ANPR cameras and software to look up and flag evaders.
In France, you pay to register a car in the first place, then the only recurring cost is fuel and insurance (and an MOT every 2 years from 4 years old). Fuel is cheaper than the UK, roads generally in better repair. Figure that out.