From wiki: “ In political science, Duverger's law holds that single-ballot plurality-rule elections (such as first past the post) structured within single-member districts tend to favor a two-party system.”
If we go to more ranked choice voting, multi-member districts, etc. then maybe third parties have a better chance. But again political scientists have been having a real reckoning of conventional wisdom since trump so you may be right on this one. But the American status quo is very structurally weighted toward two parties.