The fascists we're talking about are strictly Trump and his followers. Other conservatives are also bad, but not bad enough to overthrow the government and install a dictator.
As for the argument that a vote for a third party is a vote for the bad guy, I'm not so sure. I voted against Biden in the primaries because we can do better. But when tens of millions of people are going to vote to install a dictator, the rest of us need to be united behind one candidate long enough to defeat them. Someday, third parties will be viable, but not this year.