Generally speaking in B2B Apps, I think UX has improved quite a bit. End user workflows have improved in both usability and beauty for the masses (10-100's of Millions)
We sell software to financial institutions and our mission is to provide low-skill hourly hires the ability to reliably open complex accounts. Clearly, focusing on the ability of your target audience is really important if you want to go to this kind of an extreme. For me, this is what "UXR" is - Our team sitting down and asking "how does it feel to use that workflow?" and "If I were walking out of HS graduation, could I understand what I am looking at?".
I don't think this is really complicated stuff at the end of the day. If you let the customers harass the developers just a tiny bit, you might find high quality UXR occurs automagically.
Can you cite a single example? Web browsers, mail, event ticket purchases, window managers, music playback, file management, maps, televisions, kitchen appliances, paying for parking, paying for gas / EV charge, credit card checkouts, and banks have all enshittened in the last 15 years.
That's just stuff that actively wasted my time this week.
I can't think of any counter examples.