I think taxation is better than a ban I almost all cases. There are almost always exceptions to rules needed for edge cases, just make them expensive.
Also, climate change is something we have to fight together. How will it look if everybody is forced to do X, but the rich people on TV all do Y?
Now that the world (mostly) accepts the tragedy of the commons that is GHG emissions, it’s not so easy to justify.
Which circles back to my original comment
> Their existence doesn't really hurt anyone, I do genuinely believe that supercars are not factor in the larger climate change
Any single automobile is not a real factor in climate change. But all automobiles (including supercars) are.
If they were taxed high enough to offset that shared cost completly or even more than that it would be fine.
... but that doesn't seem to be the plan here.