In most modern democracies coalitions are the norm and one party winning and stamping their worst onto everybody the exception. Extremely uncooperative entrench

In most modern democracies coalitions are the norm and one party winning and stamping their worst onto everybody the exception. Extremely uncooperative entrenched two party systems like in the US are not very common. And guess what: in coalitions you get more of your parties program through (and thus increase the chance of getting relected) if you manage to convince the other parts of the coalition that your plans are reasonable and make some changes that they demand. Sometimes that leads to "watered down" laws that are neither here nor there, but often this also leads to better, more practical laws that are better for more people.