Back in junior high, high school, college, and grad school, the folks I played with were all physically close together. While we were busy, it was mostly with one major focus (school), and we all operated on pretty much the same schedule.
As time as gone on, a few have spawned, and they have much less free time on their hands. The rest of us have spread out over a larger geographic area, and our schedules are no longer all bent around school, so they've diversified, too.
The larger issue hasn't been the amount of time available for folks to spend on leisure, so much as getting schedules to match up so that we can all spend that time together at once.
For my current game, for example, what I really wanted was to run one big 8-hour session every other week. And, each person had such time, but the blocks were all over the place - some folks wanted Sunday mornings, others Saturday evenings, and so on. And everyone noted that weekends often and unpredictably get interrupted by other major events or tasks that can't be done on weekdays.
So, I had to settle for a shorter session every other week on a predictable weeknight.