WA has similar fees for electric vehicles and the main problem is the fact that it's a flat fee. With gas taxes you inherently pay more if you drive more, whereas EV owners pay the same regardless of how much they drive. Moreover, it's a $225 fee which is what a 30mpg gas car would pay for driving ~15k miles or so.

This TX bill seems to have a flat fee + another fee based on mileage, which sounds more reasonable.