Only insofar that the same developers work on the hardware and input drivers for both, and even frequently share code with one another, libinput also works with

Only insofar that the same developers work on the hardware and input drivers for both, and even frequently share code with one another, libinput also works with Xorg of course, and logind's mechanism for starting an unprivileged compositor was backported to Xorg as well. However, the original designers of the X11 protocol no longer even work on X for the most part, and some of them are dead. And even with the hardware it was inherited, it is true that the developer of libinput was the maintainer of synaptics, but he did not originally designed it, and found useless many of it's features that he was forced to maintain for backwards compatibility — with libinput hwas free to drop them, and initially did, but after many complaints has yielded to bring some of them back. synaptics and all the Xorg input drivers are really quite configurable allowing one to even edit the transformation matrix used for pointer acceleration directly, or to manually control the size of the touchpad scroll region, or configure rather præcisely via what criteria palm detection works — Hutterer originally removed this from libinput and considered it unnecessary overkill, but has later restored much of it after complaints, finding that many users indeed used and configured this.