Due to capacity discipline, route adjustments, etc. I am seeing longer upgrade lists for my flights. I have never seen Saturday red-eye SFO-EWR have almost 50 elites stuck in Y on a 757. That was definitely a first for me. On a SFO-SAN flight I was #9/10 of 12 on the upgrade list and turns out there were 2 GS and 13 1Ks onboard.

And I used to be based out of LAX, and now I am based out of PIT... I have to say upgrades in/out of PIT is TOUGH. I learned UA has quite bit of corporate contracts in PIT, so there are tons of Plats-GS based in PIT. My recent ORD-PIT flight had around 35 on the upgrade waitlist and I was #1 and got the last F seat.

Yes, mileage upgrades/buy ups do steal some F inventory and thusly leaving more elites in Y.