@benroyce @numodular @georgetakei
I don't know why you think the US and UK systems are so different. The UK draws the executive from the legislature, but both elect their legislatures in almost identical ways: candidates stand in geographical constituencies where they are elected in FPTP. In both cases, coalitions are extremely rare and most of the time one party wins an outright majority.
The difference is in scale and therefore the time taken to win credibility. And the fact that none of the US attempts at third parties are putting in this effort.
In the 2024 election, the largest third party was the Libertarians (Greens a distant fourth). How many state Senators and Representatives did they have going into the election? How many town mayors did they get elected? How many people who had the option to vote for a Libertarian or Green Representative for the US House was already represented by any Libertarian or Green politicians at local or state levels?