One reason we'll never get electoral reform in this country. As soon as you start asking people to show their work, they get angry and downvote you.

The dirty truth of elections is that the type of voting system matters much less than the size of the districts and the degree of enfranchisement in the population. If you want a multi-party system, you need districts small enough that minority parties can find a local majority. If you've got 400 Ds, 400 Rs, and 200 Is, you're going to produce more 3rd party candidates with districts of 100 people than 500.

That is why states like the UK, Spain, and France can produce all these small regional parties. The average electorate per constituency in the UK is around 70k. In the US, it's closer to 700k.

Do Approval Voting. Do STV. Do Star Voting. It won't save you, so long as you've got districts so large that only a minor celebrity can compete in them.