In my opinion, the best of Manjaro are Pamac and Manjaro Settings Manager.
Pamac is unique. The most complete and centralized way to get applications, doesn't matter where. You have access to: official repos, AUR, flatpak and snap, while on other distros like Ubuntu that "call themselves as easy", you need to manually go around the internet searching for a deb package, adding manually flatpak support through the terminal, search for ppas and also adding them through the terminal. They're trying to get rid of fragmentation, but still very fragmented. On the other hand, on Manjaro you have an application that have almost everything in just one place and you can easily disable flatpak and snap toggling a button, what's better than this? Pamac would be even better if it had AppImage implementation via AppImageHub, for example, then it would be fully complete.
Manjaro Settings Manager is another tool that makes a great differential for Manjaro, especially when compared to Arch where everything is manual. Manjaro Settings Manager gives you the possibility of installing/removing kernel or kernels, installing/removing drivers, auto-installation of free or nonfree drivers just clicking a button makes a real difference. It makes our life better and easy. Also, Manjaro Settings Manager comes with a way to install complex language packs for different application (a real problem for non-English speakers in other distros). Ubuntu, for example, one of the most famous distros, doesn't have such features, except the drivers and are not fully up-to-date and as easy as Manjaro implementation.
That's why I tend to recommend Manjaro for newbies instead of Ubuntu and Mint, because it's easier and it's getting better and better. Some people may be afraid of using rolling releases because of the bad stigma it has around the community as "it will break doesn't matter what you do". A lot of these thinkings comes from fixed releases/LTS users as they don't understand what is in fact a rolling release distro.