Time is expensive, all of those screenless activities cost time if you don't live near the woods/open area.
My finances changed a lot over the time I have had my children, with my first she was 3 months old when we escaped a long term DV situation, with no money, no clothes, no job, no family, into a shelter. Her whole early childhood was spent with me working 2/3 jobs. We lived in a crappy flat on a rough estate, she could not go out in her own.
Poor does not equate to stupid, we all have access to the same information but some have less options with what to do with it.
If I didn't work on the weekend to get the bus during the day, to a wood for her to run around in and play- it would cost the bus fare but also it would cost me all the hours that I could not be working. I knew that would have been good for her, she loved running and she liked trees and nature and was so excited by looking for bugs- but I could not afford to take her to do the 'free' activity. Same as I could not afford for her to go ride a bike (even if I could buy one it would have been nicked, and she could have been hurt in the process).
I could get her to the local park on the way home from school, but not for long and our area was rough and she (as a 5 year old) got racist comment yelled at her, sometimes by other mums. So yeah quite often she watched ceebeebies or our dvds because although I was with her- she could do it while I worked.
Finances changed later, our situation changed and although we never had much money, I could work one job with normal hours and we lived somewhere safer.
I could now afford to take her to the woods and to play parks and she got given a bike and she rode it everywhere and she watched way less ceebeebies and our dvds were kept for evenings together.
She was playing in rivers on weekends and climbing tress and it was brilliant- but all of then would not have been possible when she was younger and I had to work during most of the daylight hours when we could have gone out.
Free activities are not free if a parent has to not work in order to facilitate them or if they involve transport to outside the shitty concrete city they live in. Even stupid things like felt tip pens run out and crayons snap and rub away and our library was 3 miles away- so she couldn't always colour and draw or read, but she could watch the emporers new groove, because we had it and it wasn't going anywhere.