That is not even remotely why they added a tax on EVs. The reason they added the extra tax is because they make a ton of money by taxing gas and as EVs are gaining popularity they’re starting to see their tax revenues plummet. There is a nugget of truth in that some of those tax revenues are used to pay for maintaining the roads and that EVs do still put wear and tear on the roads, but it’s not that they’re destroying roads any more than any other car does.

If you’re seeing a drop in road quality it’s because your government isn’t paying to have the roads maintained like they have in the past, not because there are more EVs driving around.