> Which is why parliamentary systems are so much more stable than first-past-the-post.

I think these are somewhat orthogonal.

You can't have first-past-the-post in a parliamentary system. But yeah, that's the one dependency they have, otherwise, those are independent. You can even have weird districtal systems that look parliamentary and use first-past-the-post.

Either way, majoritarian elections are a plague and must be avoided as much as possible.