Depending on the type of riding you do and your weight+weight of typical cargo if any, some shocks are better than others - and/or last longer, from a user's perspective. Usually the first thing to go out on them is their damping, though the original shocks weren't especially good in that department to begin with.
I fitted some Progressive shocks I bought from Bob's BMW when I discovered how much the rear end of the R65 wallowed around going through twisties, and the tires, bearings, swingarm etc were all in good sort. I liked to enjoy the occasional "spirited romp" around some twistier roads, and the new shocks & springs, mated with new fork springs made a great difference in how the bike handled. They are a bit more stiff overall, than original equipment (Even when in perfect condition). The IKON shocks (reborn KONIs) are well regarded, but still often hard to find.