> If the cooling system can "take the heat", then the CPU should run as fast as it can.
The issue is what happens to benchmarks, because removing the power limit makes the limit thermal, which makes performance proportional to the efficacy of the cooling solution and other variables like the ambient temperature in the room.
There will also be variation between individual processors of the same model, since it's always been the case that some would run warmer or cooler, but now that affects out-of-the-box performance. (And with manufacturers sending chips to reviewers for testing, which ones are they likely to choose?)
This is a pretty big deal if you're a business wanting to buy the kind of small form factor desktops with cooling solutions that hew close to the official TDP numbers but you're looking at benchmarks done in larger cases with gamer-typical cooling solutions. Or people buying always-on home devices with more stringent cooling or efficiency requirements. Really anyone who wants to know how the processor would perform in an environment that it isn't permitted to continuously dissipate 180W.