I've graduated many PhD students at a top tier university. That advisor was correct. What they were doing is teaching their PhD student.

You must learn to write good reviews. That doesn't happen without writing quite a few.

Of course grad students should generate the first draft of talks, collect data, and generate graphics. That's exactly the point of grad school. You need to learn how to organize and present knowledge. How to tell a story.

>My friend said that nothing in the first five years of his PhD work contributed to his dissertation.

The point of the PhD is to learn to think about hard problems that are vague, to find your way around them, and learn how to do something new. It's not to stuff as much as possible into a dissertation or anything else.

And 6 years for a PhD? That's about right. You need to go from 0 to being the go-to expert everywhere on a totally new problem.