Why do I need bonds when I already keep a significant amount in my HYSA? I'm 30 years old

L'auteur se demande pourquoi il a besoin de bonds alors qu'il a déjà une somme significative dans un compte d'épargne à haut rendement, et la communauté lui explique l'importance des dividendes

I understand not putting your entire net worth into stocks, that's risky. But I keep one year of expenses (about $45,000) in a HYSA. That's roughly 15% of my net worth. Is that not a sufficient enough hedge against a stock market downturn? My 401k is in a target date fund with 8% bonds. That's more than I'd prefer, but I'll leave that alone. However I also have about $2,000 in my brokerage in BND, and it has barely gained anything in the past year that I've had it. Looking at historic performance of BND, not only is it down 15% in the past 5 years, but it's also down 1% all time. Like what am I missing, why are bonds so important? It seems like I may as well add that $2,000 to my HYSA.