I love watching yard transformation videos. I have seen quite a few yards in our area go pretty bad like that and I understand that there is a niche for YouTubers to work on.
As I said those yards are not uncommon simply because some people can't afford to maintain them anymore, either because of health or lack of money.
The cool thing with those yards is that you can be sure that they are not being contaminated by any chemicals. At the end of the day, it is some really good organic matter that you can get for free to start some big compost piles.