Yes, that's the basic, when you are making a comparision about specific parts of a build the rest should be exactly the same for all of the test subjects whenever possible.
I also agree that someone buying those kinds of chips is hardly expecting to game only in 1080p, the numbers can be there but higher resolutions should also be included (didn't watch the videos, so if there is also a 1440p/4K comparision, its fine).
That being said, basically every profit based outlet will be sponsored by some the brands of products they review, which means they have way more reasons to be as parity friendly as possible to avoid looking like they are biased.
Well, there are several other outlets to check, so if DF is particularly not looking good enough, one can always check another one.

You have to question why pc guys are benchmarking these things at 1080p or 720p as well.

You should be giveing people a honest representation of real world performance.
Now one buys a Geforce 2080ti to game at 720p or 1080p.

Because it's a CPU speed test, and the purpose of it is to show, which one is faster. What's the point of testing different CPUs, where all your results are GPU bound? It's like testing the car's maximum speed and follow speed limits. And yes, that would be an honest representation of the real world performance ... and also one, useless speed test. There's nothing wrong with the test. Intel is faster, and of story.

If you're limited by your GPU (whether you game in 4K or if you have lower-tier GPU), faster CPU makes little to no difference. There are plenty of websites out there, which test CPUs with a variety of different GPUs. 

Because it's a CPU speed test, and the purpose of it is to show, which one is faster. What's the point of testing different CPUs, where all your results are GPU bound? It's like testing the car's maximum speed and follow speed limits. And yes, that would be an honest representation of the real world performance ... and also one, useless speed test. There's nothing wrong with the test. Intel is faster, and of story.

If you're limited by your GPU (whether you game in 4K or if you have lower-tier GPU), faster CPU makes little to no difference. There are plenty of websites out there, which test CPUs with a variety of different GPUs. 

Yes but in the real world, everyone follows the speed limits.
So this is them showing a car that can run abit faster than another car, in a area without a speed limit (a race track or in the dessert or such).

End of the day, you and I, both use cars on roads that follow the speed limits.
So what is the point?

Which is what my point is.
No one buys a 2080ti or better GPU to run games at 720p.
So these tests that show which cpu is better (at 720p) dont serve any purpose.

Basically I think its mainly done to show Intel off, in a better light than their CPUs actually deserve.
Because in the real world, no one buys a 2080ti and games at 720p.
(its a marketing ploy, so you can say "best for gameing", and manipulate the degree to which it actually performs better at)

I don't mind them doing tests at 720/1080p as long as they show 1440p and 4k results and they did.

Using better cooling is the way they really skewed the numbers but the Intel chip is faster in games with all being equal, just not at the same margin shown in the videos. But playing these games at 1440p gives the same performance whilst one chip is cheaper, comes with a cooler bundled runs on much lower power and thermals, is more powerful overall and supports faster PCIe tech. 

It's obvious what chip people should buy but as said it's disappointing that they would heavily favour one brand in such a way.

Honest review would be:

We had to pay a lot more for the chip, put an expensive cooler to get a marginal improvement that isn't necessary to play any game at ultra setting 1440p or 4k.