What you're talking about is idealism. In a perfect world you would be correct. In a perfect world the US could have affordable and efficient mass transit within a few years. In a perfect world we could end climate change in just a few years. When your argument is based on a state of the world that doesn't exist the point of the argument is immediately useless.
This is the problem with the anti-work movement, the anti-car movement, and people who are anti-single family homes. The arguments they make are theoretically possible, but getting enough people to move in tandem to that is just never going to happen so belaboring the point over and over is just not helpful.
We live in a world where the US has 2 political parties, if one wins we get a beige moderate government, if the other wins we get Project 2025. If your idealism makes it so hard for you to determine which outcome you want then literally nothing can be done for you. If you have the idea that letting the republicans win so that then a true progressive party can exist then you need to look at history because right wing dictators historically kill the idealistic liberals and progressives right behind the Jews, POC, and homosexuals.
Nope, the thread they were responding is this one (https://lemmy.one/comment/13175909) which is about the two parties (specifically whether higher turnout would benefit one party or the other). Someone else replied saying that it's about the system being broken (itself a strawman). This guy made an attack on the person, but was still focused on the two party system. Then you made a strawman as well.