Linux isn't one operating system. It's a kernel plus a distribution — somebody's decisions about what to put on top and how. There are too many to evaluate one by one, so it's easier to sort them by what each one is optimising for.
Ubuntu / Debian
Package manager: apt.
The reason to start here isn't a feature, it's the volume of writing about it. Paste an error message into a search box and somebody has already been stuck there and posted the fix. Hardware support is broad, so it usually works straight after install.
The cost is package age, more so on LTS. If you want to track the newest language runtimes, this isn't the place.
Fedora
Package manager: dnf.
New kernels and toolchains arrive early. It sits upstream of RHEL, so you're handling what will reach enterprise environments a few years out.
Support runs about 13 months, which means you can't leave it alone. Fine if you expect to upgrade on a schedule.
Arch Linux
Package manager: pacman.
Rolling release, so there's no version number. Install once, keep updating, and the reinstall-to-upgrade ritual disappears. The AUR has more or less everything, which saves real time when something isn't in the official repos.
The manual install is what it's known for, but the part that actually matters comes later. When an update breaks something you fix it yourself, which means reading pacman output and the news feed. For people who want to understand how the system is assembled, that's the point rather than the cost.
NixOS
Package manager: nix.
The OS configuration lives in a file, and the machine is built to match it. Break the config and you pick the previous generation at boot. For reproducing the same environment across machines, nothing else is this precise.
The learning curve is genuinely steep. You have to learn the Nix language, and instructions written for ordinary distros don't transfer directly.
AlmaLinux
Package manager: dnf.
Binary-compatible with RHEL, with a long support lifecycle and no licence cost. Built for servers you stand up and then leave alone for years, and it satisfies commercial software that lists "RHEL-compatible" as a requirement.
Not the choice for a desktop or for trying new things. Stable and out-of-date are two descriptions of the same property.
Picking one
Ubuntu if you're optimising for available answers. Fedora to see things early. NixOS if reproducibility is the problem you have. AlmaLinux for servers with a long horizon. Arch isn't really chosen by use case — it's chosen by whether you want to know how your system is put together.