out if everyone who didn’t vote you would get an even spread

I don’t think that’s necessarily true. I suspect that the median non-voter is less wealthy than that of the voters.

Take other countries where voting is compulsory

We have compulsory voting in Australia. Presently we have a progressive (left of centre) government. It’s possible or likely that we will elect a right of centre government this year, but not extreme right clowns.