In my province, most store-bought spirits comes in plastic bottles.
This is true for pints, quarts and the larger 40 oz'ers.
The distillers seem to use both, for example I can get Captain Morgan
in plastic pints, plastic or glass quarts and plastic 40 oz'ers.
There are very few glass pints here anymore, most are plastic.
I would guess the quarts are about 50/50 glass/plastic.
Many larger size bottles have also gone plastic.
Some of this is due to marketing and, I imagine, some is due to provincial
regulations and taxes. If I travel to my neighboring province, it is completely
different. They have mostly glass.
We have about 95% plastic cola bottles, and another province has all cans.