I know that Memento started as a Java application, and though Java and JavaScript are both cross-platform products, Memento uses certain internal components some of which are not cross-platform, so it was Android only, and the mobile edition still is. Years later (some years ago), he began developing a separate version of Memento, also in Java, but with different internal components. Since the components are different, they have somewhat different features. Also, while Java runs on each platform, some Memento features require functions that are not covered by Java, like maybe (not sure) barcode fields, audio & video fields, and link to file fields.
I believe (educated guess) that the editions have similar priorities as each other for the developer, but the desktop edition is newer and still being built, but behind the mobile edition and getting new features as time and money allow him to dedicate to it. To some extent, the platforms are just different -- taps instead of clicks, different, often bigger file systems, and so on. Because of this, there are some features that make sense on Android, but not on Windows, and some things make sense on the Mac that don't on Android, and the same for Linux.
So, it's a very mixed bag, but with offerings from Memento include things that most of us don't even think of, like Private Server, and the Team cloud plan has less of a presence on the forum than the lower-end plans. I wrote the wiki and never got very involved with the desktop edition, which is why the wiki is so Android-centric. It's not that there is any preference on my part. It's just that I'm retired and a lover of soft furniture, which is more suitable for tablets than for laptops.