If someone trained smart sticking to the best and most efficient compound movements could probably even do alright with only twice a week?100% agree, people say that they dont have time etc etc, this is really all it would take.
3 days a week, 45mins to an hour doing weights. Throw in warming up, travel, changing etc. Its really just 1.5 to 2hrs, 3x a week.
If one of those days is on the weekend, two days during the work week should be almost always achievable.
Single people, 100% definitely. I can appreciate those with families and the issues surrounding that.