I'm still soured by how the primary shook out in 2020. Before any votes were cast, all everyone said about all the candidates were that anyone could beat Trump. Bernie won the first 3 races, and the Democratic establishment fought anyway they could to kill the movement, including pressuring flailing campaigns to back out. Biden finally won and the only message is for the left wing of the party to get in line. Kind of a hard pill to swallow when the Democrats claimed to be the party of the youth, but the youth voted 80%+ for Bernie in the primary. Ended up voting Green in 2020. Will I do so again in '24? Who knows, but at this point it isn't looking good. I don't like that the right wing of the Democrats (center-right overall) expects the left to follow along no matter what they do.
I'm not sure I buy this whole "third party votes are wasted votes" or "third party votes are a vote for the opposition". The US system heavily heavily biases towards having a two party system, but third parties exist, and just because Democrats and Republicans are the two major parties right now, doesn't mean they will be in the future. The Whigs were one of the two major parties for 25 years of US history, even winning the Presidency a few times, but now they're not. It took people not willing to accept the party line and jumping ship to change that, which again the system biases against, but it still happened. Democrats aren't the end-all-be-all of lefty politics. The next left wing party won't be the end-all-be-all either. Democrats have no incentive to change the current system. By continuing to vote for them, whether you believe it or not, you're approving and perpetuating the behavior. It isn't a useful method of change to say "I don't agree with anything the Democrats say, but that's the world we're in". That's how you end up in a situation where 70% of the country supports universal healthcare, but only 5-6 members of Congress do. Voting for a further left party than the Democrats will cause the Democrats to wise up to what their traditional base wants.
Politics in Democracy is not a passive system. Passivity leads to what we have now, two parties that write the rules for the states and the governments that represent the interests of almost no one, but have convinced us that they're the only and best options. There are agents of the Democrats currently in jail for breaking election law in their efforts to keep the Greens off the ballot. I'm sure the same is true for Republicans. Don't tell them its okay by giving them your vote. Don't give in to the political version of the Paradox of Thrift.