I think it's one of those things where people only care about a small percentage of the features, but which small percentage varies.

For example, I used the example of remote play together, which is very neat and a lot of people love it, but I personally don't use it.

On the other hand, I make extensive use of Steam's gifting feature, including its ability to handle multiple gifts to multiple people in a single transaction, and to schedule exactly when those gifts will land. And this is something that the other major stores don't seem to support at all, a big advantage for Steam for me, but I'm sure there's many people who don't care at all about gifting.