For Colorado, it looks to be based on weight, but varies within a pretty narrow range. It's the use tax that is pretty steep in the first few years and based on the original MSRP that can make the difference between newer and older vehicles. I've got some more research to do; but, do hate the idea of paying hundreds each year just for the privilege of owning a vehicle.
You are paying for the privilege of using the roads, although license fees are a poor proxy for that.
Colorado vehicle registration includes "OWN TAX" (ownership tax) on the new vehicle cost. If you itemize deductions, this portion is deducible.
The passenger vehicle & light truck tax is based on the original sales price of the vehicle, and starts at 2.1% for the first year, declining to 0.45% for years 6 - 9. For years 10 and beyond the OWN TAX is $3/yr. (I’m not certain if the value is set by the actual purchase price or the sticker price of the new vehicle. This could be expensive for a new EV if the price isn’t reduced by incentives.)
Additionally, there are flat fees, currently totally about $100, depending on county and state fees.
I have chosen to own vehicles that were at least 6 years old because of the structure of the license fees.
Overall, Colorado is a low tax state. My property taxes in Denver run about 0.52% of market value for my condo and rental house.