The customers of those products are generally computer illiterate and don't understand it anyway.
You can dig out the information if it interests you.
If you need the power of the i7-7920HQ you should have a Ryzen 7 tower PC.
If they tell you the numbers you might compare performance to cost increase.
i7-7700HQ @ 2.80GHz 8962
i7-7820HQ @ 2.90GHz 9373 +$100 for 4.6% CPU upgrade. In complex video editing, you save 3 seconds per minute.
i7-7920HQ @ 3.10GHz 9990 +$200 over 7820HQ 6.6% upgrade. or $300 for 11.5%
[PS add- Ryzen 5 1500X scores 10477 as better than i7-7920HQ for the purposes the laptop is for. That is a $170 CPU]
In typical usage, about 95% to 98% of the time, you would not even notice the difference.
It's not a secret marketing trick. It's a marketing trick to fool almost everyone, including you in knowing the CPU numbers unless you actually look them up and think about a laptop and its usage.
A Macbook is awful at gaming, so you are only considering massive video editing and incredible 3D animation and processing. The graphics processor for the high resolution screen is so weak at the price, they are bad at graphics animation also anyway.
They are using AMD Radeon Pro because of the resolution, or they would use NVidia.
The top Radeon Pro 560 is well below a GTX 1050.
The answer to your question is that very few people actually understand computer hardware.
Those that really do know where to find relevant information.
They also kind of leave out that their SSD is almost the best available, but upgrading it is major issues.
The 256GB is about $118 value retail.
The 512GB would be about $225 (Apple gets $200 over the base $118 value)
The tb about $425 (Apple gets $400 over the 512 or $600 over the 256GB)