For the first line, sure, "everybody" was clumsy shorthand, every eligible American voter on redcafe in 2020, who nearly all went blue.
Why the "partial responsibility"? Why not "sowing what they reap"?
Why the "feel bad"? Why isn't it "on their conscience"?
If a 3rd party voter, who didn't vote Trump, is directly responsible, why are the actual voters, the ones who gave the President Biden the mandate to do the war crimes, any less responsible? This is backwards logic. One is primarily responsible for one's owns actions.
The only reason this disparity in responsibility, which is inversely proportional to the directness of the connection between their votes and the final outcome, seems to exist, is to soothe the consciences of the majority of people who do the "lesser evil" vote.
Finally, I will again note that this is an academic debate. Transferring every single Green vote to Kamala doesn't reverse a single state, and she needed to reverse at least three to win. It is even more academic when this forum's one American third party voter did what you asked for, and voted for Kamala.