I’ll continue advocating for reforming an existing entity instead of chasing unicorns.

Almost every high functioning democracy in the world has managed to populate a credible multi-party assembly. To pick some random examples, the UK has ~14 different parties seated in its legislature, Canada has 5, France 12, Sweden 10, Germany 9, the Philippines 13, Japan 10. These aren't cherry-picked either, you can pretty much choose any country and go have a look at its assembly makeup, and you'll consistently see that the ones with only two parties are... not good company to be in.

The only thing stopping America from electing a government that represents the views of its people, are cheerleaders for the status quo using circular logic like yours.