You’re arguing against a straw man. I’m not voting for Biden because someone else is telling me to vote for Biden. I voted for Bernie in the '20 primary, but he lost and threw his support behind Biden. Biden got the most votes in the Democratic primary. Rather than view that as someone “telling me who to vote for” I recognize that is the reality of our primary system and first past the post voting system.
Now the choice is Biden or Trump. I agree with Biden on 80% of issues, and agree with Trump on maybe 5%. I don’t think anyone criticizing Biden is “an idiot,” I think anyone saying “both sides are the same” is an idiot, because the difference between their political positions is incredibly stark