The amount that it drops per year has little to do with the volatility or stability of the asset. If the loss is a gradual 3% grade that slopes down in a straight line that's a perfectly stable outcome as far as UoA is concerned. Whereas if it's up 5% one day and down 10% the next day with an average of 3% down that's a completely different scenario.
If I can pick an asset at random and attach a price to it: like $10 for 5 pounds of apples ($2/pound), and you can tell me if that's a good price or a bad price, then UoA is working. If not then not.
That's a great way to put it.