Bottom line: You should vote. You shouldn’t vote for Harris. You should vote for Trump if you are in a swing state. Otherwise, you should write in either Ron DeSantis or Nikki Haley.
My reasoning: Harris is the most left-wing nominee ever of any major U.S. political party. You just can’t vote for her if you are a conservative. The problem with not voting at all is that no one will know why you are not voting at all; if you don’t like the offered choices, you can clarify that by writing in your preference. The Republican Party needs to be told that it should not be nominating irresponsible nonconservatives such as Donald Trump, and the message will resonate more strongly if those votes are concentrated in one of the two also-rans, fine choices both. But I’d rather wake up each morning knowing that Trump, rather than Harris, is president and facing what he has in store rather than what she does.