Meaning the calls to primary were not serious.

How are you reaching that conclusion (especially when just 4 hours ago you seemed unaware that people were calling for it)? I think they were serious. But they were rendered moot because both Sinema and Manchin announced they weren't seeking re-election before the 2024 primary season started.

Time and again voters complain then reelect the people they are complaining about. That’s why the DNC are not even campaigning, they know they can do jack shit and voters will still vote for them.

Incumbents win re-election so easily because voter turnout in primaries sucks so they don't have to spend hardly any money or energy to be nominated again. Here in Texas, we had 3.2 M voters in the 2024 primaries, out of 17.9 M registered voters. And 2.3 M of those were Republican primary voters. So only ~1 M Democratic primary voters, selecting who will be on the ballot in November. Now you can try to blame that on Biden being too old and unpopular to motivate people out to vote, but that's just passing the buck on voters removing their voices from the literally every other office that's up for election. Biden being the presumptive nominee for president in no way takes away your voice for all those other offices that have 100x more impact on your daily life. And at the start of it all, you have to have better candidates actually willing to run in the primary in order to vote for them in the primary.

Many feel trapped by the system while they keep supporting it because they have been convinced there are no other choices

But they're not participating in the process of selecting the candidates that will be on the general election ballot. One million Democratic primary ballots cast in a state where the previous mid-term general election had ~3.5 M Democratic votes for the statewide offices and the previous presidential election had 5.2 M Democratic votes. And to be clear, there were 8 candidates for president on the 2024 Democratic primary ballot in Texas.

and anything but a vote for their oppressors is a wasted vote.

If you are aligned left, and you vote in the general for a 3rd party, you are reducing the number of votes the Republican candidate needs to receive to win. That is a mathematical fact in every precinct in this country where a simple plurality of cast votes determines the winner. Pointing it out is not a suppression/oppression tactic, it's a plea to learn how the system is designed to function because we won't overcome its intentional problems by sitting on the sidelines.