A tax is self-adjusting for updating technology. And it changes it from a get-past-the-post system to a do-the-best-you-reasonably-can system--which would be better as the best place for the post is inherently unknown and often can be gamed. (Observe SUVs displacing station wagons. SUVs are regulated as trucks, not cars.)
Yeah, they started playing this game as soon as emissions standards started. My old IH Scout has 3/4 ton suspension which let IH put a truck engine in it in 1976 with none of the smog controls that were required on cars at the time. Still, air quality improved a lot even with companies gaming the system as best they could. Automakers claimed for years that the smog control required killed performance. But they eventually figured that out and now I have a Honda Ridgeline that will run circles around the sports cars built in the 1980s (acceleration, breaking, and fuel economy) and can still easily pull our 18' fiberglass bay boat or haul a cubic yard of rock home for a project.
A tax certainly has the potential to give the market the most flexibility to make efficiency meet the target by pricing the pollution to be avoided into the market. But, a downside to the tax is what politicians do with the proceeds. If the tax is lucrative then they are apt to dip their fingers into the pot to pay for other things. Then if cars or buildings or whatever get really efficient then the tax revenue drops and they have to go hunting for other revenue sources. We end up with moving targets and a need for side boards no matter what tool is used to achieve.