What keeps working, based on the accounts here, is the core of the mouse: the clicks stay consistent, and the shape holds up as a daily driver. Owners who recommend it do so without flagging degradation over time.
The long-term reliability picture is thin. Only three owners commented on build quality, and the accounts are split: one mouse died after the warranty lapsed, one owner ranked Razer below Logitech for reliability, and one had no issues at all. Three accounts cannot support a conclusion either way. If longevity is your main concern, the data here is not enough to answer it.