I literally do blame the Democrats for Trump, and if you don't, you weren't paying attention.
Plenty of us were critiquing Clinton's campaign on those merits and were consistently talked down to in shocker the same way we're being talked down to now. Shocker, she lost. I remember saying a few weeks before the election "We're about to get Brexited." I put my vote down for Clinton, because Trump is fucking insane, and that was clear before he was President. It was clear in the fucking 1980's.
Being able to critique our leaders is supposed to be what is the difference between us and conservative voters. They're the cult who unquestioningly believes all the bullshit that comes out of Trump's mouth and diapers. I find it weird that people think we should be more like them in regards to our leaders like that would be a good thing.
Voting is but one of many political actions you can take, and you're right that voting can no longer lead to any meaningful positive change, but it can stop things from getting worse too quickly.
Real progressive change will require external pressure via direct action / protests / civil disobedience / alternative institutions like unions and mutual aid. If you're upset with the state of things then participate in some of those things, but do not withhold your vote. Voting for Dems may play into their too idle hands, but choosing not to plays into the hands of the fascists trying to destroy our democracy.