Nobody said GS isn't valuable, but exceptions are a big part of why it's valuable.

But it's more than that. When was the last Mercedes transfer you got? Other airlines have restored that.

Upgrades as an AA EXP happen far more frequently than as a UA GS, with upgrade rates falling for years.

Other material downgrade off the top of my head:

• United stopped giving status benefits to people that you book on award tickets, which meant a huge devaluation for GS awards booked for others.
• United stopped selling first class and closed down Global First lounges that GS members could access even when not flying first class. I don't expect to see VIP lounges reopen. This also meant the end of opening First class saver award for space for Global Services members, which had much better availability than business saver.
• The ability to create saver economy award space (based on T class) was changed from a benefit that you could book for an unlimited amount of people to one that could only be done if the Global Services passenger was flying and for only one additional companion.
• The ability to create saver business award space (based on PZ class) was changed from a benefit that you could book for an unlimited amount of people to one that could only be done if the Global Services passenger was flying and for only one additional companion.
• The ability to create saver business award space for a companion (based on the Global Services member having a paid business class flight) was changed to just one segment of an itinerary instead of the full itinerary. There also now has to be at least 2 seats remaining for sale after the saver award seat is issued.
• The ability to force domestic upgrades by requesting within 24 hours of a flight was removed.
• United used to offer Marriott Platinum or Titanium status to Global Services members, but now it has been downgraded to Gold, which is a worthless status that no longer awards breakfast.
• There used to be no hold times for Global Services members, but hold times have increased in recent years. and the quality of agents has gone down.
• This isn’t really a devaluation per se, but Global Services members are escorted to the front of the Pre-Check line in some airports and I used to consider that one of the best benefits of the program. However anyone with CLEAR can pretty much get the same benefit these days.
• Global Services members got waived award close-in booking fees, but now get hit with close-in fees on the form of extra miles.

Am I nitpicking? Maybe, but saying the devaluations when taken as a whole are minor reminds me why UA takes the slowly boiled frog approach.