I believe referring to our system as a "two party" system is mistake. In the United States there are far more than two political parties, although two specific parties dominate electoral politics. BUT, continuing to refer to the system as "two party" simply perpetuates this belief that there's no reason to vote for "third" parties, even though "3rd party" candidates DO get elected. Most of them are at the city council / county board of commissioners level, they they get elected and hold office.[1]

And as long as we stick to this incorrect single dimensional model, we make it even more difficult to talk about 3rd parties, exactly because some (many?|most??) of them don't fit the simplistic left/right continuum. To continue with an earlier example, American libertarians do not fit cleanly on either side of that model. I'm pretty sure there are other examples, but the Libertarian one is the one I'm most familiar with.

It's something of a chicken-or-the-egg problem, granted, but right now it's probably easier to start changing the language we use, than it is to overcome first-past-the-post single-member-district voting systems, etc. [2]

[1]: https://www.lp.org/candidates/elected-officials

[2]: https://en.wikipedia.org/wiki/Duverger's_law