With the introduction of Wayland, some things like clipboard handling have changed to be more restrictive. There are commands like xsel and xclip (with same package names) that exist to interact with the clipboard. However, these seem to need wl-clipboard (package) to be installed to work properly.
rpm-ostree-based distros rely on a reduced but functioning base image, I think wl-clipboard should be included as a default package in this base image.
xsel and xclip are two different Xorg only tools, and are not related to wl-clipboard. All these tools have their own command syntax. The wl-clipboard package includes the separate tools wl-copy and wl-paste for copying/pasting.
You are right. I looked deeper, now into the code instead of relying on documentation or package dependencies. It seems that an application recommends using xclip or xsel, but the library it is using knows about a few more cli tools. It seems like wl-copy is used, but the dependencies do not reflect this, nor does the application documentation. Bad request on my part.