I think you’re missing how markets work — if demand crashes, prices will too. Take a look at the recession and housing values; once people couldn’t buy them, demand went off a cliff.
Govts absolutely need that revenue, but you’re mistaken on the weight. A Toyota 4Runner is about 4,800lbs. A Tesla Model 3 is 3,800. A Mercedes C300 is 3,400. Not much difference.
The simplest and cleanest solution is one tax on gas, another on EVs per mile — both tax people equally on use, which seems fairest.