Does the Nitrogen Testing Method truly provide the accurate Protein content in Whey Protein Products

We have seen many Youtubers providing their reviews on products based on the Nitrogen testing method. But are these tests accurate ? A lot of known companies get away with this test by Amino Spiking or by simply adding Melamine which boosts the nitrogen and is determined as protein in these tests. So is it fair to just give a product ranking only based on these tests ?

I personally use a product and only then give a feedback keeping all parameters in mind.

What are your thoughts on this ???