Your argument is unironically "real Liberalism hasn't been tried yet." "critical theory" and "identity politics" are not "weird offshoots," they are unavoidable consequences of Liberalism. No matter how many times you try Liberalism it will degenerate into exactly the current situation we are facing now.

Failing to acknowledge the structural flaws of Liberalism just opens up an opportunity for ideological revolution. If the adherents of Liberalism prefer moderation, they better had start acknowledging how it's failing people. "Just Liberal harder" won't work forever.