This is absolutely terrible advice and is out of touch with modern financial understanding. Bonds feel psychologically safer, but lead to failure more often than total market equity portfolios, even when you account for market crashes.

https://youtu.be/p25PPBgMiEk

I agree with everything in the video you linked (which is not surprising, given it's Ben Felix). That includes the parts about equities being less risky than bonds in very important ways, but also the parts about behavioral loss tolerance and risk capacity, and how they can indicate higher bond allocation.

So I disagree that "If you're dreading equity drawdowns, that's what fixed income is for" is absolutely terrible advice.

I always thought the psychological safety was exactly part of the point, since 100% equity portfolios do better in theory than practice, because people are more likely to panic sell.