My hot take is that the two-party system isn't anywhere near as bad as people think it is. In countries with multi-party systems, parties often have to form coalitions in order to govern. In countries with two-party systems, parties have to do most of that coalition forming before the election. That's why we see far-left and center-left politicians in the Democratic party instead of having viable left wing parties.
One way or another, we get a coalition government. Is it better for those coalitions to be formed before the election or after? If it happens before the election, the electorate can see the results in time to change their decision. If it happens after the election, the fringe parties' arguments probably get discussed more, but there's no guarantee those parties will be part of the governing coalition.