The things which differentiate distributions of GNU/Linux from one another are less numerous today but still an important factor in many user’s decisions. There can be differences such as installation methods, the target CPU architectures, and what governs the entry of software into a distro’s repository. But some are felt much more immediately by the user. Distinctions which will affect the day to day usage of the system. Here are the most notable, in my opinion, ranked from most impactful to least:
There has been some homogenization in the area of init systems, leaving a divide in distros which have built atop the understandably maligned systemd and those whose distinguising mark is the fact that they don’t. Package managers still dictate how users acquire and install their software, and the landscape has only expanded now with the addition of universalized software packaging with things like Ubuntu’s Snaps. Desktop environments, as well as window managers, command the largest position in the way users interact with their system.
The catch is that any of these things can technically be changed by the end user, but this is not always obvious or easy. Most will accept whatever is the current default. And so we end up with people who, in order to sample the different options, will jump between the different available distros. An activity they refer to as “distro hopping”. But consider that most of them are just trying out the various desktop environments all while oblivious to the fact that many distros, like Arch or Debian, allow and even encourage their users to select their own DE/WM from a wide range of options. All contained within a single distro.
Those who reformat and reinstall distros in order to try out the available GUI environments are not distro hopping… they are desktop environment hopping. To anyone who may be in the grips of such an activity, I suggest instead identifying a distro which has your preferred init system and package manager. This is because those are usually more laborious to replace. Then simply install and add your favorite DE or WM through your package management.