I admire all these young folks having 2.13m networth at such a young age.
When I was 30 years old, I had 0 in my bank Account.
How times have changed.
I personally feel its not where you start but how you end

.
A lot of FIRE enthusiasts are limiting their earning runaway by wanting to FIRE at 40, though the above blogger with 2.13m in his late 30s, should have no problem FIRE with 3m in his 40s if he wants to.
I think 50s is a better time, gives you 10 more years of earning to build up your funds.
By taking it easier rather than rushing FIRE, you can also take care of your health and maintain fitness better.