It *should* reduce waste, assuming the manufacturers don't keep pumping
out so many new ones that they also sit on the lots for a year at a time.
Unfortunately, they do.

Not for long. Apparently you haven't been paying attention to what's going
on in Detroit these days. Excess capacity is being sold off and shut down
as quickly as possible. It would be happening much, much faster if not for
the formidable obstacle of the UAW. But it is happening. The survival of
the domestic auto industry depends on it.

You really need to develop at least a modicum of faith in free markets. It
is not a false religion.