Polly Toynbee looks at the political state of the world's two main FPTP democracies.
https://www.theguardian.com/commentisfree/2021/feb/16/two-party-electoral-system-factions-voters
There are differences between the US system and the British system. The British system has always been partizan and adversarial. For as long as I can remember, the ruling party can usually expect no cooperation from the opposition at all. In the US system, there was an expectation of being reasonable and working together when it was agreed to be for the good of the country. In fact, their constitution requires it to work properly. For example, the constitution provides a means to remove a corrupt president before his term is up, but it requires members of congress to put the country ahead of the party and their own jobs to function.
The Republicans have realised that, if they stop playing "fair", they can gain an advantage. That's why American politics is in such a mess at the moment.
There are other problems as well, which I might discuss later.