I think anyone will concede that depending on the location and interest rates, the math can be close. But 4% on a CD and 6% interest only loan? That is not realistic.
also it's not a fair comparison: yes with a mortgage at the beginning your payments are 99% interest, but in the last 5 years they're almost entirely principle, so you get to keep that money.
if you're still renting in 25 years 100% of that money is still going to the landlord, and your rent has likely gone up by a factor of 5 too.
ALSO over long periods of time real estate nearly always increases in value (more than inflation), so that's another thing to consider.