This may seem coldly logical but in the absence of my own researched opinions, I am evaluating the merit of the opinion about these interviews based on their origin:

You have - companies that settled on this process, who have been able to attract top tallent that has cleared this bar.

You have - employees of these companies that were able to clear the interview bar.

And then you have - people who don't work for these companies, proclaim to have no interest/ability to clear the bar, but claim to have a valid view into where the bar should be.

In the absence of other data it doesn't seem like the last group is likely to be objectively right