I would happily have a decade of declines or stagnation on the 10's of 1,000s in the kids account over the next 20 years - they can then invest in their productive earning years in companies trading at p/e's of 10 again.
The anti-correlation between bonds and equities hasn’t been a thing for decades. That is advice that passed its sell-by date a while ago.
The modern version is to go hard into equities and out-grow the drawdown risks. You still want a couple years of burn in treasuries but that is strictly a buffer against adverse returns. By the time you retire, the treasury fraction is a tiny fraction of the total by virtue of the equity growth rate.
I don’t have any reason to think that international economies are not correlated to the US. But also I don’t expect them to be that successful. Europe and South-east Asia have a mafia like relationship with their established businesses and regulate away new ones.
The sibling comment addresses bond funds.
ZIRP, 2008, Covid, trump, big tech, and AI all came after Boyle.
But 7% is not the risk free rate! The S&P and these other things have risk!
But show me a bond I can buy that’s paying 7% and I’ll show you below investment grade.