You'll note that the current flat-fee setup on registration in effect penalizes most owners for having EVs. They pay more, for the generally lower mileage driven, that they would if they had s similar gas-powered car. I'm pretty sure that was the intended outcome when the fee started, because EVs==EVil. Though I have to admit that whoever leased the one I now have, new, definitely did put the standard number of miles on it - it has about 35K at 3 years. Since then, I've added about 3K in over a year. Yeah, Covid, and retired. Low annual miles driven does reduce the insurance a little.

The main reason for considering VMT taxes instead of fuel taxes is exactly what you mention: everybody using the road should pay their fair share, no matter what they're "burning". There may be cases, as for pedestrians and perhaps bicycles, where it's simply impractical to do that directly, and the impact is miniscule anyway (except for those wannabe racers and pace lines...). But whatever happened to the California Bicycle License? I have one on my bike, bought it when I bought the bike, but there has never been a procedure for renewal or anybody to keep track of them at the state or even local level. I think it was just a token fundraising mechanism for local fire depts, which was where they were mostly sold.