Responsiveness. This is relevant to me because I have older hardware. PopOS was a hard no for me because even its installer was laggy on my system. Once installed, it was okay but worse than others.

App compatibility. I know that all distros can run anything but the ease of it is different. For example, Lutris did not open successfully in Debian but it opened easily with all others.

Flatpak support. Again, all distros are compatible but for some reason Debian gives error while downloading Cisco packages. I have never seen it with anything else.

App Store. It is a good idea if there is ability to browse system as well as flatpak packages in a store. This is not an absolute necessity but nice to have.

Desktop environment. This is probably the most subjective and irrational criteria. Some distros just click, like Mint Cinnamon. And some others just don’t, like Gnome. I can install any DE on any distro but I prefer the out of the box versions.

Popularity. This is very counter intuitive since distro choice is personal but I am not a techie who can verify code on my own. So it is best if an existing community does it for me.