Tell that to all of the HNers from Europe who are constantly complaining here about how low their salaries are, compared to the US. I doubt this rule applies to most tech workers in Europe. In fact, I would say it only applies to US workers in the top 25% of companies. The rest are just grinding it out in a slightly-above middle class job: 75K-100K USD.
As long as you are just expecting math and not a generalizable strategy for retirement. The "simple math" behind Mr. Money Mustache is: Have no mortgage, multiple properties providing income, a blog providing income (including making recommendations of financial services that provide him affiliate income), and have nothing go wrong with your life financially or health-wise... and then you can retire with no[1] income! OK I'll get right on that...
Similar formula behind other get-wealthy motivational writers: Sell lots of books to people who gobble up get-wealthy motivational books, and collect royalties for life.
MMM is Personal Finance Porn: A story of one guy's very lucky and privileged life path, not generalizable to everyone else's situation even though it's sold as that.
That’s Pete’s personal situation, but the simple math works for anyone (especially most western tech workers).
You have to be willing to curtail your consumption, which gives a double effect (lets you save and invest more and you need less from those investments).
Not everyone wants to do that, but that means they won’t retire early.
...and don't get seriously sick, and don't have elderly parents that need expensive care, and don't have family overseas who need financial support, and make sure your kids don't get accepted to an expensive university, and and and... then you can apply MMM's very generalizable advice.