It depends how you look at it.
Ranked Choice is not going to make a third party viable at the presidential level. Simply because the other two parties have orders of magnitude more funding to campaign and make sure people know and “like” their candidates. And, depending on the implementation of ranked choice, it may still result in splitting the vote.
At the congressional representative level? Ranked choice has a lot of benefits there. But that is also the level where third party candidates are still viable under the current model.
The reality is that most of the things people want out of ranked choice we already have out of the primary system. Wide range of candidates run in the primary on each side. Primaries exist to figure out who The People like and to let the party down select. Done right, you have what would otherwise have been “third party” candidates who suddenly have a LOT of influence within the party (see: Bernie Sanders in 2020… less so in 2016) because they get a lot of influence on the platform in exchange for supporting the candidate who has the majority of the vote and the party backing.
The key is that people need to understand they are still compromising to get some of what they want AND to engage with their local (and even national) parties to make sure their voices are heard.
I mean… none of that actually helps a third party at the presidential level. Or even addresses spoilers. Going to address your points out of order to make my own
So… the third party candidates get eliminated in the first round. Because they cannot compete with the two big parties in terms of campaign funding. Assuming it doesn’t end in the first round because…
So the republican wins because there is one right wing fascist running against a dozen flavors of Left wing. Or the Democrat wins because all the third parties were a negligible percentage of the vote to begin with.
I HAVE seen proposals that change the ordering so that a third party “can’t” be a spoiler (I forget the specifics but basically it is removing the small percentage votes first and only comparing once you downselect to N candidates where N is usually 2) but…
People confuse the idea of making a third party candidate viable with minimizing how much you are pissing away your vote by voting for a third party in the presidential election. Ranked choice is great for the latter but it still has many of the same spoiler problems without additional changes. And, arguably, would increase the impact of third party spoilers if one party over-splits. I continue to point people toward the mess in France where basically all the Left wing parties had to unite and make a coalition to MAYBE stop the right wing fascists.
Personally? I would much rather we abolish the electoral college and just do a popular vote. That will have a MUCH bigger impact on third party candidates because it suddenly becomes viable to run a national campaign where you convince maybe 15% of the overall populace rather than needing 40% of each county just to end up on the politico map. Because the latter is what really screws over third parties at the presidential level because they just don’t have the money or resources to sway enough counties to get any meaningful electoral college votes. And ranked choice alone has no impact on that.