Have a hard time reaching customer service? That is because they added friction to finding the number on purpose. Have to wait in the phone line and go through a maze of electronic voices before being able to talk to a person? Friction. That tax form seems needlessly complicated? Friction.
Friction is an essential design component of any system and some of it's uses are also legitimate.
Sometimes you want the costly action to have a small cost on the user side as well, which will act as a filter for people who really need your help, for example.
Let's say for example you have a self-service platform for students and they should be able to change their name. Now you could do that frictionless, but a name change is not frictionless in the bureaucratic backend of the student office. That means representing it to the user as a simple frictionless process, when it isn't is a misrepresentation of reality. Then it is better to represent it as a thing they can request and have to wait for till it is done.
Ideally of course the student office would have systems where names can be changed 10 times a second with flawless forward- and backwards-compatibility, but that isn't the world we live in.