Just cos he's at Chelsea and their cattle farm does not mean that he's "good" or worth the original fee they paid.
They bought him for £30mill. He started 2 games in the prem last season, hes a year older. Yet his value hasn't diminished.
You wouldn't do the same with a car.
Cars depreciate due to usage and improved technology (younger footballers aren’t coming through built with better tech)
Houses for example appreciate due to inflation almost regardless of usage…
Neither of these have anything to do with a football player who did play every game in their European cup winning season if I remember rightly and is only 27