If you’re retiring so early and with such relatively limited wealth, then over the next half century plus, what happens when:
(a) Yields, dividends, interest rates, etc. fall?
(b) There’s a bout of inflation?
It’s not good enough to say, “Oh, I’m getting $X/month of dividends today, and I can live on that.” That doesn’t cut it. There’s nothing guaranteed about 2% interest rates, 3% dividends, or today’s inflation rates. There are even some countries with negative interest rates right now, and there are also some countries with high inflation.
There is a possible way to combat these risks. Let’s suppose you retire at age 40. You could buy an immediate lifetime annuity from a high quality insurer that pays a guaranteed real (inflation-adjusted) level of income, for foundational income (slightly more than enough to survive). If you actually do that, that can work and is reasonably safe, especially if combined with substantial non-annuity assets.
These risks are not unique to early retirees, but they are more acute the earlier you retire.