I don’t normally advise my customers of the longevity of prints, but most of my stuff is only intended to last three years anyway.
It would be interesting if you compared it with something more recent because I would hope that in the last four years some improvements have been made to the ink and also to the UV protection from the laminate.
I’ve only had my printer since the beginning of the year so can’t really comment on your experience but I have to say that have been surprised by the resilience of the print. One of the first jobs I did was rally type plates for a 4WD expedition company. In discussion with the customer it was decided not to laminate as they only needed to last for a week, the duration of the event. He kindly agreed to leave one of these plates on his Land Rover and I looked at it after six months. In comparison with a new one there was a bit of fading, but not much and I was very pleased that it looked so good after half a year. He then told me that apart from the scorching sun in places like Morocco it had been through five sand storms and numerous steam and pressure washes.
I still wouldn’t normally put unlaminated on a vehicle, but I was very impressed with the performance of my prints.