So what's the winning strategy? Let Trump win instead?
The world isn't perfect. Holding out for a perfect candidate means never voting, at which point you have nothing to bargain with either.
Go ahead and vote your conscience in the primaries, sure. It's not such a big deal if you hold out for perfect in those. But in the American election system the actual vote for president is going to be between Trump and Biden. It sucks but you get just those two options there.