The 15" Razer Blade is throttling worse than a touchbar MBP, and the 17" does much better but still far from maintaining 4.5 ghz as you claim.
But then again, I don't understand the comparison. The Blade is surely a capable gaming alptop, but its CPU performance is subpar compared to the MBP, the screen quality is average at best and the battery performance is low-tier. Not to mention that it is heavier by a whopping kilogram (including power supply) and bulkier. I wouldn't consider a Blade for my main computer. I mean, in the end its just an expensive toy (unless you do something that needs a large GPU and you don't care much for mobility, at which point jut get a desktop).
And of course the MBP can't compete with a dedicated gaming laptops, but it does very well in comparison with other premium segment multimedia laptops (e.g. Dell XPS, X1 Extreme and others), while also being a serious work tool. The point is not about buying a laptop for gaming. The point is having a serious daily driver that you can also use for gaming. Why would I spend additional 2k on a toy if I can just game on my main machine anyway?