Yes, because many people choose not to save. While not everyone could save $100/month (double the amount I mentioned), almost everyone over the age of say 25 can. This was attainable for the majority even 40 years ago.

Again, Americans can save more, the savings rate skyrocketed for instance during the pandemic even as unemployment increased dramatically, they choose not to: https://encrypted-tbn0.gstatic.com/images?q=tbn:ANd9GcQFv4v6...