When I was with NWA WorldPerks I got many upgrades on longhaul flights. Then I changed my address to a Middle Eastern country and had to move to Flying Dutchman, and then the upgrades stopped altogether!
Only last February, and maybe 6 years after the last upgrade, got a pseudo-upgrade! Was flying from Mexico to AMS on KLM and the Business class section was totally empty, so they selected a number of PEs to fill these empty seats!! Only that because the service continued to be economy.. Didn't bother.