Yeah, with the current system, the only real hope for a major third party is for one of the major parties to split. Because any small third party just eats up the votes of the major party closest to its position. But, big parties only tend to split when they face major electoral defeats and there's a lot of infighting. That means that not only did they lose, but now due to being split, they're not even an effective opposition, and the other major party wins more easily than ever. (Which tends to lead to complacency and corruption, which tends to lead to eventual electoral defeats, once the other party gets its act together...)

And then there's the problem that the only people who have the possible power to pass electoral reform belong to one of the two major parties, and it's completely against the interest of those major parties to get rid of FPTP, because FPTP locks in their duopoly. That's why, for example, when the Canadian Liberal party promised to get rid of FPTP, they abandoned that promise as soon as they were in power.

Maybe reform is possible because people are human, they don't always optimize for the perfect win in a game. But, game theory says that it's going to be a major uphill battle to pass any kind of reform.