There are some advantages, when compared to extreme cases in the multi-party spectrum.
For example, Israel has had 2 elections and still hasn't managed to choose a PM because no stable coalition has been possible so far between parties that dislike each other. For a while, Italy's PMs averaged 1.5-2 years in their job.
Multi party systems, depending on the circumstances, can also degenerate into horse trading, government pork and kingmakers parties. This is when a small party is needed to give the governing party a parliamentary majority. In that case, a small party can sometimes exert outsize influence on policy by insisting on particular treatment of something, even when the majority of voters are not sympathetic.
In BC, we've recently had our 2, or 3rd, referendum about moving away from first past the post voting. Guess what? Despite a whole lot of online claims of their moral superiority by people fond of proportional representation, the referendum came out more than 60% in favor of keeping things as they were.
Note also that the US isn't quite as much an outlier as all that: France for example pretty always elects presidents from either the center left Socialists or the center right party (Macron being an exception). Canadian elections generally either get a Liberal or whatever the center right conservative party calls itself, although minority governments do happen. UK elections: Labour or Conservatives. So, in practice, these countries don't have that much variability in their core parties.