Not voting or voting third party is letting other people decide.
Biden is a bad candidate. He's too old and supports genocide in Palestine.
Trump is not fit for office. He's too ols. He's mentally deranged. He supports genocide in Palestine, fascism in USA, NATO being at war with Russia etc etc.
Voting least bad is a poor choice to make but there is a very clear answer.
It's the same in the UK. I live in Australia, having moved from Ireland and living in the UK. It blows their mind when I talk about PR, yet we have it here in the Senate.