The notion that PR leads to nothing getting done is mostly a myth, excepting a few very unique exceptions. The majority of Western democracies use some form of PR, the US, Canada, and Britain are the major (only) holdouts. Britain does not use a PR system unless something has happened that I do not know about.
I imagine talking electoral reform with many Americans will invoke notions of the boogie man of socialism because the power centers have done such a good job over recent years of falsely conflating a proper electoral system with the desire of PR supporters to give people everything and thus ruining their desire to work.
Those who like to spread misinformation deliberately, or who just don't really understand PR well like to point to countries like Italy and Israel as examples of the dysfunctional nature of PR. Those two nations are extremely unique in modern western democracies Italy was a nation cobbled together from quite few autonomous regions with striking degrees of division and competitive leanings and it has continued to play out that their parliamentary efforts which are still characterized by strong regional squabbling. Israel is a nation divided deeply over security and the question of expansion and occupation of territories surrounding their state. While we have regional differences here in North America they have historically not prevented a greater degree of cohesion around central issues. That is of course changing.
Do you believe that in Germany, Sweden, Switzerland, Denmark, Norway, Australia, New Zealand, France and others that they get nothing done in their governance? All of those nations have PR systems. I think if you look at Germany you would have a terrible time proving that they get nothing done. I'm sorry if I sound argumentative, not at all my desire, but the notion trotted out that the US system is somehow a shinning example of a truly democratic electoral system is demonstrably a very, very flattering depiction. Do you think the Biden administration (if it comes to pass) will be able to get much done? I don't. I suspect American is in for some rough years on that front.
First-past-the-post electoral systems in all of their forms and guises were tools of the elite and wealthy that guaranteed that even if they let the people have a vote, while on the surface it is "democratic", ultimately nothing important in terms of their economic control and power would ever be threatened. This isn't theory, it is science and has been studied at great length and subjected to intense peer review. In political science and economy studies there is very robust study around democratic and electoral systems. It isn't just some crazy ideas hatched by a bunch of lazy hippies who don't want to work and dream up ways to get a free ride. I wonder how democratic Trump supporters will feel the process is if they lose?
And yes, first-past-the-post systems are associated with two party systems because over the time they essentially guarantee that will happen to one extent or another.