Desktop clutter
Desktop clutter is just the same problem that most people have - not having an organised way of keeping things. We all do it to some extent, say the "downloads" folder that fills with all sorts of stuff and eventually you have to clear it out to recover many GB of space.
Some companies have well-structured systems, typically a network share and some corporate standard for how projects, contacts, invoices, etc, are all to be organised and stored in a hierarchical system. That is why directory trees are so good. Also good to have it centrally backed up.
But it takes either a very organised mind-set, or someone high up clamping down on folk, to get that done. Instead some places in the local file system (like the desktop) become a cache of recent or possibly useful stuff. But it hardly ever gets tidied up in the way you might have to do each week in an office, etc.
Is there an easy solution? I doubt it, as things like stacks, etc, are just attempts to make an ad-hock file grouping (e.g. folders, directory tree) to do what is not being done by the person. But even the claims of AI to help are unlikely to work well. The other approach of removing the desktop (the sort of move loved by the muppets behind Gnome, for example) is really a bit if intellectual fascism - deciding how you *must* use *your* computer because we tell you so.