Although ranked-choice voting (more precisely, instant-runoff voting) is a step in the right direction, it will not solve this problem. Yes, it lets voters safely express maximum support for a third-party candidate that’s guaranteed to lose. But as soon as that candidate gains enough support to become a viable threat to the two major parties, the game theory doesn’t work out so nicely.

Approval voting is a much simpler system that gives better results.

https://www.electionscience.org/library/the-spoiler-effect/