Do high-ranking US grad schools typically interview PhD applicants? I am planning to apply for Engineering PhD programs in the US this Fall; however, I am a bit confused as to whether US Engineering grad schools typically conduct interviews for PhD applicants.

I had assumed that most of the institutions that I am interested in would be conducting interviews of PhD candidates, to help gauge the personality/cultural fit. This view was reinforced by a friend of mine who did a PhD at one of those schools a few years ago, who told me they were interviewed.

However, I have spoken to another source that I consider to be reliable (basically, someone closely connected to the faculty of that school), who has given me the impression they don't do interviews for their grad school - they base everything off of the paper application.

I was a little surprised to hear this and so I am wondering if it is typical for fairly high-ranking US grad schools not to conduct interviews? Is there a general trend, or does it vary quite a lot from school to school?

Note: I have edited the question and title to take a step back from the apparent misconception(s) I seem to have had, and ask the question I probably should have started with in the first place. Hopefully it won't affect the validity of any of the answers.
I have not seen anything to indicate that PhD programs no longer interview candidates. I was interviewed in person by many (~75%) of the schools I got into for my PhD program in 2015. I doubt this has changed in 4 years. In fact, I helped interview several candidates in 2017 and 2018 at my school. I was invited to tour and interview at several well regarded schools in my field. 

Note that some schools do not interview candidates. This is especially true of lower -tier schools in my anecdotal experience. But I had colleagues who interviewed at some rather prestigious schools in Massachusetts.