The Democratic Party lost to Trump, not "the left" and they lost based on either: not opposing the genocide in Gaza or because even ostensibly progressive voters won't vote for a black woman; there's only two data driven possibilities and neither of them is "culture war/identity politics has just gone nauseatingly overboard"
and of course the idea that the Republican Party hasn't been running on "identity politics" would require a wilful ignorance and complete lack of thought about any of their campaigning in the last few decades.