Active noise cancellation is very good at steady low-frequency sound — aircraft cabins, train rumble, air conditioning, road noise — and much weaker against speech and sudden sharp sounds. Any pair marketed as blocking out an open-plan office is overselling; what they do is lower the floor so speech becomes less intrusive.
At the flagship tier the differences between brands are now small and mostly about signature: one house sound is warm and thick, another is neutral and detailed, a third leans on call quality. Comfort and clamp force matter more than any specification, and cannot be assessed from a spec sheet.
The practical advice is unchanged for several years running: buy the previous flagship. Cancellation performance improves slowly, discounts arrive quickly, and the money saved is substantial.