I don't think mandating voting really helps that much. At best, you'll get people to vote for the candidate with the (D) or (R) next to their name. What we need is for people to be more informed. Fewer than 20% of people can name their state legislatures, let alone their stances.
Mandatory voting doesn't fix all the problems, but it's better than the alternative. Instead of campaigns focusing on "go vote" you get campaigns focusing on the actual voting.
https://hub.jhu.edu/2018/12/14/americans-dont-understand-sta...