You must be incredibly lucky to almost always get upgraded. All one has to do is spend some time in places like FlyerTalk to see how difficult it is to score upgrades, even for the most elite of travellers. Back in my heavy travel days (UA 1K+) doing similar volume as you claim, my upgrade success rate was at best 50% and with credit cards now allowing any old Ma and Pa Kettle elite status, all reports are it's even more difficult. After a few years of minimal biz trave (so no status), last year I managed to make PremPlat on UA/ I've got some flights coming up soon and I have zero expectation of getting an upgrade and I know there will be plenty of 1Ks ahead of me who won't get upgraded either.
Unless you are something like Global Services (on UA - but all the major lines have similar), I highly doubt you are almost always getting free upgrades and if you are GS, you are GS because you are likely buying F seats outright.