Some that come to mind...

Marriott EEOs (elite exclusive offers) were BOGO weekend nights at most full service Marriott brands that came with full benefits. The EEO certs suffered a long and painful death along with "Marriott Concierge" here on FT.

Meaningful upgrades to a better room or suites that were actually available. No SNAs or groveling necessary.

Full selection of welcome gifts that had use and value. Fruit platter, desert plate, wine bottle, beer bucket etc. Most hotels had a welcome gift menu at FD so there was no disputing the guarantee.

Hot breakfast in lounge or restaurant. Now the T&Cs are changed to "continental breakfast".

Multiple MegaBonuses where you could add 100s of thousands of points each year.

Rollover nights.

PP elite that earned UAL Gold.