Fun fact: instead of cupholders, 1970s cars would proudly advertise the number of ashtrays they had equipped the car with, usually 1 within reach of every seat. This number was equally important as horsepower or price on marketing materials.
The same people doing that now would have been doing it then also. It's so easy to put an ashtray in your car, or just an old soda can, and people used to care a lot less about "littering".
I have a 2015 car. Imagine my surprise to find that it has front and rear ashtrays. I hadn't seen an ashtray in a car since probably the early nineties. I remember for a while after the ashtrays stopped being standard that you could order a "smoker's package" to get them, but I thought that option had long since gone away.