This is great until you have dependents and your expenses grow. It requires everyone to be on board with your vision which is a lot more challenging to maintain over time.
You are absolutely right. It's much harder to do with young dependents. I'm 55 now and my son is 27 and daughter 24!
However, I still think the same rules apply. Ram down expenses as much as possible. I did this when my kids were much younger. I couldn't get away with working 3 months a year, but I often did a six and maybe a 3 and had 3 months off. Back then I'd spend the free time with my kids. These days because they do their own thing I head off to Phils or Thailand and go diving.
Obligatory link to mr money mustache. He has a great blog on keeping expenses low and living a frugal post tech lifestyle. https://www.mrmoneymustache.com/