Six years is certainly lucky, but it's easy to save working as SWE. There are people living in your city on a tiny fraction of your income. A person without commitments could save the entire diff, if they wanted to.

And travelling is cheap as well, I have a friend who is travelling long term for like $300-600 a month, including all the transportation costs, etc. (The opportunity cost of not working is obviously much higher though.)

Yeah for real. I think that any dev can retire by 50 if they want to. Maybe by 40 if they really put in effort, but if you're retiring before your mid 30's you're either 'leanFire' meaning you've basically committed yourself to a life of relative poverty or you somehow got hold of a 'lotto ticket', and that, by definition is extremely rare and not something anyone should plan for.

Kind of depends. Plenty of people COULD live like a monk and save a ton over 6 years. But that requires not having a family and likely not enjoying your life very much. I probably COULD live on significantly less than I make right now. Hell, I have in the past.

But I sure didnt enjoy it very much.

But if you lived on rice and beans in the cheapest place you could find while making a 6 figure salary... Saving a very significant sum every year would be possible.