The most important thing for most new Linux users would be a pathway to getting support. Because of this the distro you use matters much more than the DE because each of the major distro's have different pipelines that the funnel users in to getting support. The package manager lock in is distro dependent and depending on the philosophy that they subscribe to can be the difference between how many steps a new user has to take to get a working system up and running. Thankfully, with the rise of flatpak, appimage and snap being more popular than ever package availability is much more streamlined but that is another layer on top of an already overwhelming package system for new users. The defaults for all of this depends on your distro which can be different. Heck we haven't even gotten to support cycles which depending on user needs can be different. Because not every user has or wants what comes with for example maintaining an rolling release distribution. Did they setup their system to have snapshots so they can roll everything back when the new kernel update breaks something system critical and they have a presentation at 2:00? None of these things are really DE dependent but are baked in to the defaults you subscribe to when you choose a disto. The good part is that if you don't like how something is configured you can change everything easily depending on how well documented it is. This is why it's more important to choose a distro with good documentation or at least a active enough community so when you run into hangups you can get some sort of resolution.