Or maybe there's both factors in play, and it is something about my rig that gave an improvement whereas it seems it's been great for others since U13.
It's never been great, good, or even mediocre. Aliasing is still obtrusively bad in Odyssey, even at very high resolutions, with multiple filtering passes.
That's why it's important not to give Frontier the perception that they've fixed something they absolutely have not...the surest way to delay a fix is to cause doubt that the problem still exists.
Care to show some screenshots of this improvement you're claiming? Or of what you were seeing before?
The performance ceiling matters. A good example is often shadows on a CPU limited rig - turn up shadow quality to max and you will find the FPS ceiling is suddenly below the GPU's floor... at which point it doesn't matter where that floor is theoretically.
The existence of a relatively low, CPU/memory limited, performance ceiling makes the game's poor AA standout even more. I can run the game at 5k resolution and still not be GPU limited in a large settlement CZ, yet still have blatantly obvious aliasing on every high-contrast edge.