It’s also made much worse by defrost cycles. During a freezer defrost cycle the air temp in the freezer will often get above freezing. It shouldn’t be above freezing for very long but it can be long enough for the surface of food to thaw very slightly and then refreeze again. This is why food lasts longer in old school chest freezers. Those freezers don’t have any automatic defrost so food isn’t repeatedly slightly thawing and refreezing.
It’s also made much worse by defrost cycles. During a freezer defrost cycle the air temp in the freezer will often get above freezing. It shouldn’t be above freezing for very long but it can be long enough for the surface of food to thaw very slightly and then refreeze again. This is why food lasts longer in old school chest freezers. Those freezers don’t have any automatic defrost so food isn’t repeatedly slightly thawing and refreezing.
Chest freezers also don’t lose nearly as much cold air when opened compared to upright.