"There might be appetite for a third or a different party, but the winner take all principle in the US electoral system pretty much makes only 2 party system viable. In countries where also minority parties are represented in a parliament etc, you will have multiple parties. There are pros and cons to both."
That is true and the parliamentary system can be bogged down by too many parties. But for now at least, we are certainly seeing the cons of the American system on full display.
Trump is doing everything he can to scuttle the US election and to discredit the US voting system. Should this result in major changes to the US system, would't it be ironic if, inadvertently, this actually turns out to be his only real legacy?