There are many alternatives and RCV might not be your first choice, but make no mistake about it: FPTP has to go. Stat.
Partisanship is generally good,or at least not bad, in democracies.
Having two big-tent parties that shift platforms in search of a minimal winning coalition renders partisanship into empty tribalism, which is bad.
> people looooove a “bipartisan” bill
Bipartisan bills are the worst because they typically represent consensus of the (otherwise fragmented) elites against the people.
> but FPTP mathematically converges on a two party system, always.
FPTP creates structural incentives toward a two-party system, but voting behavior and party membership is not mathematically-determined behavior and thus no vote counting system “mathematically converges on” any party arrangement.
> To see this in effect, consider that a major party is incentivised to fund fringe opposition parties which will steal votes from the main rival.
And yet they rarely do; more often, and mor perniciously in practical effect, is that they are incentivized to negative campaigning since getting someone who would otherwise vote for the opposition to not vote is just as good as getting someone who is undecided to vote for you.
> There are many alternatives and RCV might not be your first choice, but make no mistake about it
IRV is very nearly the worst even semi-seriously advocated method that isn't FPTP (I won't call it RCV, since there are many ranked choice methods and IRV is worse than virtually all the rest.)
It is so little of an improvement over FPTP that I suspect the harm it would do to the entire idea of electoral reform through the disappointment it would produce in failing to fix the problems motivating a change in voting system would outweigh the very slight improvements it would produce.
What's more, I'm tired of driving 7.5 hours to the boardwalk every time I want ice cream, and then not being able to find any parking spaces around the exact center of it, where the vendors tend to cluster.
Since FPTP mathematically converges on two parties, the two parties also mathematically converge on the perceived political center, and then advertise in opposite directions from the same spot. When the voting is structured to prioritize how far customers are willing to walk for the flavors they like, rather than going the shortest distance to the only flavor available (vanilla), we all get more choices.
There is a mathematical theory about this, but it assumes a number of things that aren't true about real political behavior (basically, it ignores that political engagement that matters isn't limited to voting, and that voting behavior isn't simply “every eligible voter will vote, and will vote for the candidate nearest to them by some political distance function”; it may also ignore that distribution of political views is neither uniform nor unimodal with a central peak, but instead has peaks away from the center ), and empirically doesn't seem to predict the actual behavior of parties very well at all.
 it's not clear if it ignores this or just doesn't consider distribution because distribution wouldn't matter if the things it does ignore were true; certainly some of it's defenders seem to think that political views are unimodal and centrally-peaked and that that mitigates any problems from the other oversights, which it might, if it were true.)
There are better single-winner systems that truly fix this problem, of which the clearest example is approval voting.
FPTP is probably here to stay because of pure inertia. The rest of the claims need support.
Also, 'Republic' is a meaningless description of a country, because it conveys no practical information about its form of government. Norway is not a republic. North Korea is a republic. Canada is not a republic. Russia is a republic.