IT actually exists to help ensure people can do their job, and do their job faster. As a general goal, I like to learn about people's business processes for the exact purpose of seeing how our IT environment can be improved to expedite their work.

And having five browsers on a PC doesn't make it easier for end users. I have no problem dealing with five browsers, but I get a lot of complaints from people when they open link A in browser B and link C in browser D and don't understand why things don't work.

You may have experienced poor IT departments in the past, or thought you experienced poor IT departments because you didn't understand the other considerations in play, but that's hardly an excuse to assume any given IT choice is some sort of attempt to prevent employees from doing their jobs.