I live in Sweden most beekeepers here use polystyrene hives , I have a college that has a poly hive that is 30 years old , probably needs a new coat of paint ;)
The poly hive is light weight , easy to move , = spares your back = can keep beekeeping when your old and frail , or if you're Young and not so strong.
Warm in the winter , spring ,for brood. It also insulates against heat in the summer sun
Ventilation is a little backwards.
Spring and summer fall reduce the bottom ventilation , = earlier start for brood , easier for young bees to sweat wax , draw comb.
In the winter open the ventilation over the bottom of the hive ventilates condensation lets air in despite of dead bees.