"People on itch.io" ranges from hobbyist teenagers to professional full-time indie devs.
The utility of a press kit varies rather a lot, depending on if you actually get any coverage. For example, I do not anticipate any media outlets caring about my project, so why would I spend time making a press kit?
For someone who has some amount of klout, a marketable project, and ambitions to earn a living doing this, things definitely look different. But those people are a small minority among itch.io developers.