Primaries are a bit crazy. But they do have an interesting effect of spotlighting different candidates, putting them under pressure l, and see if they hold up. That's not necessarily bad, but the order of contests means that when you get the spotlight has a dramatic effect on the number of votes you get.
Thinking of Trump as a far-right candidate is, in my opinion, a misread. He's operating on a different axis. Many of his policies are center-left: no wars, peace deals, love letters to Kim Jong Un, the First Step Act, massive stimulus, and inner city programs.
His main positions on the right are conservative judges and the border wall. He kind of went crazy on those two things, and did a bunch of other non-partisan crazy things. But overall he doesn't fit into the left/right divide.
Too many candidates running on a similar set of issues will split the vote and will lose against a less popular candidate running alone on a different set of issues. So they end up needing to consolidate (which can involve some wheeling and dealing like promising that the candidate who steps down will get a position in the remaining candidate's administration).
This is essentially what happened in the 2016 Republican primaries. The more moderate candidates never consolidated and so split the vote among themselves. By the time they had seen the writing on the wall and dropped out, Trump had built up a large enough margin that the only remaining candidate (Cruz) had no chance at catching up.
RCV will likely prevent a similar outcome in the future. But a further consequence is that candidates will have less incentive to drop out early in the primaries. So if RCV were instituted nationwide I would expect the primary season to be longer, messier, and much more crowded.