Social democracy as a concept would work if those doing it would have a spine and not be traitors of the working class.
No, it wouldn't, because the thing they want is still capitalism, and everything they do (riding on actual workers struggle) will be inevitably dismantled as soon as capitalists gain the upper hand again, as we observe time and time again. Socialdemocracy itself is a class treason and was born from class treason.
Even socialliberalism is still for capitalism, meaning it is right wing ideology. Not to mention every single time any declared socialliberal gets elected it turns out they are just ordinary neoliberal austerity ghoul.