Its really not applicable to unlocked CPUs, which is where all bets are off when it comes to the cooling you then need to keep it performing as you want.
But for locked CPUs, the last ten-fifteen years we've seen Intel stretch the turbo at the expense of base clock, just to keep winning benchmarks, because the sustained performance isn't there like you say... 2.8 Ghz and we're singing praise because its 300 mhz above an abysmal 2.5? Come on. In 2013 the base was 3.4 Ghz or better.
We can explain this in various ways, its not all negative, of course Intel CPUs are pretty flexible on voltage and turbo which has long kept them the efficiency crown, but at the same time they've created a complete mist around what their clocks actually do and they're using it to market the turbo, not the base, while the latter is what most people will see a lot more of. The end sustained performance of last generations has been largely stagnant, which is the true story.
It depends on what you use the CPU for. What I talked about is a sustained all-core workload, which I think most people never see. In fact, in games, I see clocks in the 4-4.3 GHz range and power consumption around 50-60 W - and that's with the IMC in gear 1 and the iGPU enabled for dual display. It's easy to scoff at modern Intel CPUs for their ridiculously low base clocks and high power consumption in all-core loads, but the truth is, in real-world scenarios, they're quite conservative with power, thus letting clocks sit in the commonly acceptable range.
If you're a content creator and run Blender 24/7, that's a different story.
Edit: Also, GHz in the past and GHz today can't be compared. Intel was stuck on 4 cores for a looong time. Today, with 8 cores, my locked 11700 at 2.8 GHz achieves the same Cinebench score as a Ryzen 5 3600 stock. I know, it sounds ridiculous (it probably is), but let's not forget that 1. you don't really need more for games, 2. this chip is a lot easier to cool than a 3600 in SFF situations (that's the only reason I bought it) and 3. with a proper motherboard and cooling, you always have the option to unlock it, bringing it in league with the 5800G and 5800X. Sure, it eats around 160 W then, but you have 4.4 GHz all-core sustained. I'm not saying that it's brilliant, but certainly not as bad as people and the media like to believe.