Linux distributions have definitely standardized over the years. You get a kernel, systemd, network manager, Firefox, etc from basically every distro targeting desktops. Most will have different spins for the popular desktop environments as well.

From a purely technical perspective the main difference of distributions today is the package manager. Are you using pacman, apt, dnf, or something else? We know as users that while some of these different package managers have advantages and disadvantages they are all doing the same thing. You can get basically all the equivalent packages on each major distribution. I sometimes feel sad thinking about all the volunteer effort working in parallel, but not together to package the same software using different package managers. In many ways it’s duplicate effort that I wish could be spent in better ways.

Even package managers are beginning to converge. Flatpack is becoming extremely popular and is my current preferred way to add software to my system.

Leaving technicals behind the only major difference I see between distro today is their philosophy on how frequently to update and what to exclude. Does every package get a new update immediately when it’s rolled out upstream like Arch? Are we going to stick to older packages and only apply security/bug fix updates like Debian, or do something in between? Do we want to bend over backwards to make it easy to install Nvidia drivers or tell users we don’t support closed source software? Do we want to make it as easy as possible to install codecs or leave it to the wider community to figure that out on their own?

I don’t think there’s any right or wrong answer. Use what you enjoy!