Now, even if we take some specialized tasks that need more CPU (but are niche anyway):
- For image processing, we had Photoshop doing wonders since at least 2000. And with SSDs, we can view and edit 30+ MP images today faster than we could 8K images back in 2000 (and on 4K displays nowadays). We can very much cover all things web and print just fine.
- For video processing, a fast latest box can edit several streams of 4K with live filters. That's beyond what $200,000 professional boxes could do in the early nineties.
- For audio processing, a MacBook Pro i7 can run more audio channels and effects than what the consoles used for Thriller or The Wall had in million dollar professional studios.
We also need to understand the concept of diminishing returns. E.g. It's not like having an NLE rendering time down from 2 hours to 1 minute will enable us to make more movies. It will just save some editing studios and amateurs some time. Other processes involved in movie making (like just setting the lights appropriately for a shoot) trump this "optimization" many times over.
So it's not like people "need" faster processors. It's more like they would be "nice to have".
Now, for things like HPC for research etc, could indeed use faster processors -- but that's an even more niche market.