I fly pretty frequently for work and get upgraded maybe 40% of the time to first class
What airline still does that? What are you gold or diamond level or something? I see empty seats in first class all the time (while seeing the frequent flyers board early... in coach), and know of frequent fliers that used to get upgraded ten plus years ago, but not anymore. The airlines are cheap cheap cheap, and I haven't heard of them giving anything away for free, including upgrades.
For crying out loud, I often see the emergency exit aisles partly empty because people won't pay the extra that the airlines want now for the leg room.... This means there are frequent flyers that are on the plane that did not even get "upgraded" to the exit aisle (if you can call it an upgrade when it is just an exit aisle).
You are the first person I've heard say you get upgraded. I'm flying soon and I will ask passengers and crew, and I will ask the people I know who work in the industry.