>why are used sellers so out of touch

Math.

You don't see what sells because it's no longer on the market.

A vehicle that sells in 1mo is on the market 30x longer, seen by 30x more people, etc, etc, than one that sells in 1d and only takes 1/30th as many of them on the market to fill up your FBMP feed.

Now, not a lot of cars are priced to sell in 1d, but also 30d is a comically low upper bound as well. Adjust the numbers as you see fit.