Yay, this conversation again!
A modern engine- and especially a turbocharged direct injection one - has such a wide range of operating parameters that power output widely varies based on a multitude of things, including fuel quality/octane, intake air temperature, engine and transmission temperatures and much more. Timing and boost are constantly being fiddled with to hit an ever-changing load target determined by the stock tune.
Power levels can easily fluctuate +/- 20hp in a short span of time. This is why marginal claims like “adds 10 hp” or “shaves 0.1 seconds in the quarter” are dubious at best and an outright lie in most cases. It’s nearly impossible to control for exact parameters but it’s really easy to exploit them.
Yes there are theoretically restrictions in the stock intake. In fact a culvert would flow even more air than an aftermarket intake. But there is absolutely no point in serving up more air flow potential than the motor can demand or make use of, certainly not at the expense of filtration effectiveness. Fine grains making their way to the turbo is not great. Not worth the gamble in my mind.