I feel like I'm of two minds about this, as all of the pieces from rags like the NYT use analyses that assign 100% of the depreciation of the car to driving, which is obviously absurd: your car loses something like half it's value the minute you drive it off the lot. For some reason, none of the analyses I've seen attempt to address this (in fairness, it's probably pretty difficult).

The upshot is the difference between unlocking wealth that was going to be unlocked anyway, and unlocking wealth that was going to be wasted. A person's car is a criminally underutilized asset (from both a personal finance and a societal perspective), and increasing its utilization so you get more value out of it during its trip from full value to $0 is a concrete gain for both society and the Uber driver (and along the way, passengers and Uber itself).

The dynamic you describe is certainly a factor too; It seems to me to be an open question how big a component of an Uber ride's value each of these is. At any rate, I don't think your confident assertion that being an Uber driver is simply giving up your liquid asset value is warranted.