Cool, Biden's the progressive one and supports women's rights and queer rights, especially trans rights too (hasn't always been the case, even).
What if he didn't, though? What if the party line was to similar or exactly the same to that of the Republican party? Would you still enthusiastically tell everyone to vote Democrat because on other topics he's the “lesser evil”?
If every election is just harm reduction then a completely new strategy towards elections and parlaments needs to be formed. I've explained my thoughts on harm reduction here already, so I won't repeat them. You only got two parties, but the fact anyone, even someone not liked by the Democrats, can run in the primaries is powerful. However, reading Bernie Sander's new book shows how much manipulation was put in his way by the Democratic party's leadership in order to prevent him as a presidential candidate, so even there we need to work on multiple fronts at the same time.
We need an syndicalist, intersectionalist, and internationalist left. If every option on the ballot is always throwing one group, or almost every group of people, under the bus, and these groups or their interests are being weighed against one another instead of realizing that all rights or needs can be fulfilled at the same time if we stand united, we will never achieve peace both internally and internationally.