You keep on saying this, and I get your logic. I actually agree with the premise.
I think you're being naive with your perceived end result though. You seem to think that if black people just didn't vote, one party would come rushing to us the next time to give us things to vote for them. I question how much you actually pay attention to politics if you believe that. For example, the Dems have been down with the youth demographic since Obama, but they keep doing shit that turns away younger voters. Right now Biden is down so much with Muslims that he's projected to lose key battleground states, he's not change course to court them. The Dems temporarily tried to blame the loss to Trump on a downtick of voting from black men. In other words, we've already seen an example where they thought us not voting was part of the reason they lost. When Biden came around the next election cycle, did he go out of his way to court black men? No. Not only did he not do that, but he put Kamala Harris on his ticket, someone who had a reputation of being anti-black male in the way she did her job.
It's all well and good to tell black people to stop supporting politicians that won't do anything for us, but you got to stop acting like that strategy is some foolproof plan that will guarantee us leverage. It's not. Black people make up < 13% of the people in this country. We've been eclipsed by Latinos quite a bit. There's a good chance that if black people refuse to be the Democratic Party's tool, they'll just find another one. That's the reality of our shitty political system, and one that you and others never want to acknowledge.