In Australia, and I assume the Netherlands, the transmission network is separately owned and run by government corporations. While multiple private companies are allowed to generate power and sell to customers on the government owned grid.

I suggest you watch that video again. He agrees that high sodium increases blood pressure. Most of his points are about how it affects people differently and other lifestyle factors that affect blood pressure such overall diet and exercise.

There are copious studies showing the link between excess salt and hypertension and heart disease. This has been well established for decades