Ranked choice would allow independent voters who choose to opt out of voting for one of two major party candidates to still vote for their preferred candidate that best suits their ideology but not have their vote be a vote against the major party that more closely aligns with their ideology. For instance you could vote for the green party in a swing state but have a democrat in the second tier so that your vote doesn't elect someone whose ideology is opposite yours.
Third parties have often been the impetus for change because one party typically takes on their policy initiatives if the lesser of two evils causes them to lose an election. With the bipartisan system becoming more disparate, many advocates of solutions to modern problems go unheard and the issues get swept under the rug.