Zero taxes are a good incentive for drivers to switch to EVs, so if the goal is to get people to switch, it might be a better idea to wait. Call it a subsidy.
To the contrary - that's a good reason to subsidize the construction of of infrastructure, but having some sort of incentive to use less damaging forms where possible makes all kind of sense. Part of the reason for the stupid-sizing of consumer vehicles in the US over the last decades is because the incentives are all messed up.