Which type of PC isn't going to dayburn. Is it silicon (photo diode) or CdS (photoresistor). Probably I know that CdS photocells drift which sometimes causes to dayburn. Which one is best for lifetime performance?
Regarding the sensor itself, the silicon photodiode is way more stable, so it is expected to be longer lasting.
But that sensing element is not the only part of the whole device, there are way more parts to go wrong, so if they are of questionable quality, they will fail sooner.
And because the "dayburning" is a bit more acceptable failure mode than "dark at night", practically all decent products are designed to more likely fail into dayburning than into OFF (of course, the most preferred way is still to not fail at all).