I just had a boat come out of charter
. My feeling is that they get used hard, by people who either don't care or don't know as much about taking care of the boat as an owner would. However, they are also maintained to charter ready conditions.
I think privately owend boats will vary more in both extremes. Some will be used very hard and neglected. (often why they are being sold) Others will be in pristine condition and lightly used. I've certainly seen non-charter boats for sale
that are in much worse shape than my charter boat was a the end of it's contract
The market has a way of finding a value for all boats.