At what point did they say both parties are exactly the same? They said both parties are evil, and both parties support colonialism. The commenter is evidently disillusioned with the two party system, but they aren't stupidly saying to not vote Democrat. They're asserting that neither party will make the country better.

While the idea of better is highly subjective, let's try being charitable and see it from the commenter's viewpoint: They sound like a socialist, so let's assume they want political reform and more legislation to protect the poor or working class. In the current two-party system, everything is gradually shifting right. The Republicans are more brazen about their goals with shit like Project 2025, while the Democrats only have to be less regressive than the Republicans to have a successful platform. The Republicans don't want reform, and there isn't any incentive for the Democrats to implement progressive changes (such as implementing RCV, banning gerrymandering, introducing SCOTUS term limits, etc.) when they can be equally successful by simply reverting the damage done by the Republicans. Considering that perspective, they're correct in saying neither party will make things "better." The part that isn't said directly but can be inferred is that one of the parties will make things worse much quicker than the other.