It's really important to note that populist arguments often hinge on the idea that there is an elite that's disconnected from the people, and it's easier to make that argument if there is an elite that looks very different from the average voter. For example, in the U.K., at least in the post-war period, more working-class people entered politics through trade unions than they do now. These days it's very difficult to be elected as a politician in Britain if you don't have a university degree and if you haven't come from a relatively privileged background, and that creates a disconnect.
It's really important to combine measures to improve the representation of women and ethnic minorities with measures to think about how we make parliaments more accessible to people who don't come from privileged backgrounds.