The thick plastic player with the ridges is pretty resilient, but above that is a reflective layer for the laser, and a protective lacquer layer (often printed on). If those layers get damaged and delaminate due to harsh handling, UV / heat, and / or moisture getting between them then the laser will have difficulties focusing and thus reading a disc.
Should still last years in such an exposed public free library setting where long-term preservation is probably not a goal, and get way more use out of them than sitting in personal closets where they’d last longer.
Because they don’t understand that voting is just one part of the democratic process.