Great UX makes a world of difference. UX is about more than just features or appearance: it's about everything coheres together as an experience for users.

UX should be relatively easy to copy, but it seems (at least to me) that many people have a hard time copying UX. Many people will copy features or appearance, but their execution usually lacks something. This is not a dig: most people don't get it.

There are a few people who do, and when they create something new, only afterward does it seem so obvious.

This is just my take.