He doesn't know something. He's guessing like every other investor. In every distribution there are outliers. There will always be a best and a worst. Buffet's the best but he doesn't know anything about the future. He's been wrong before.
BTW, what I read is he's down to around 50% in equities. I don't know if that includes anything beyond his core. (He doesn't call me. I wonder if he's still mad about that time in that place where that thing was,.) And 2% in bonds. I think there are cash accounts now that pay around 5%. That's a good yield in uncertain times. If his investors are satisfied with CD rates, more power to them. It's their dough not mine.
You think it's Biden's economic policies, but it could just as easily be the collapse of tech workers and middle managers and fast food workers and such due to AI. Who knows? Everyone is always playing catch up. If your answer to everything in life is "Liberals," you're like the guy who only has a hammer so every problem is a nail.