Ironically, that was one of the biggest campaign points and voter sentiment on which people flipped to Red. We all know what happened.
Sitting out of the process does absolutely nothing, whether its a protest vote, pretending that politics don't affect you, or just giving up completely. The people who get elected in those situations always 100% ignore you.
When people are in office that are at least willing to listen, you then make a lot of noise and put on pressure. You might get ignored mostly, since you are a minority voting block, but you can make incremental gains and even sometimes big wins.
I certainly found plenty of folks who were not only okay with the DNC's position but who were actively happy with Harris as the nominee.
Black people are, however, not a monolith. I'm quite aware of the differences between the many different sets of ideas (everything from hoteps to DNC-paid shills to people who genuinely liked the Harris platform to black anarchists/commiunists/ ex-panthers/ etc) and it's highly reductive to try to make the claims you're making here about "what black folks have learned".
As a person who genuinely believes actual leftist (communist and anarchist) politics are legitimate I found plenty of folks who abstained or tried to hold the DNS to change their policy.
But regardless of the "harm reduction strategies" or how legitimate you think having any semblance of political representation, the fact remains:
the democrats lost.
Unless you want to concede that "the party can only be failed, it cannot fail the people", the reality is that the party could have changed its policies and accommodated groups that abstained and perhaps won.
You can claim that the voters are just fools, but at the end of the day very few of us have any power at all over the DNC platform so it's simply bizarre to blame us for their horrible, provable failed choices.