Bonds are a waste of time. Persuade me I’m wrong

Basically, title.

Bonds are much more correlated with stocks than ever used to be the case. I thought of them as hedges, once upon a time: but patently they are not that. Are they even realistic diversifiers? I’m going to say no in the hope that someone can persuade me I’m wrong (or confirm my suspicions).

I rebalance in December each year and am sorely tempted to balance bonds out altogether. They go up when stocks do but not as much, and when stocks go down so do bonds. So what is their purpose?

Currently I hold 65-10-10-15 eq-bond-gold-MMF, the MMF to avoid sequence of returns issues as I need to access some of these funds (basically what I know I need in the next five years is all in the MMFs).