It's true that dependency-free software is very rare these days. The most obvious reason is that people don't want to "reinvent the wheel" when doing something. While this is a 100% valid reason, sometimes people simply forget what they are building and for whom. Extensive usage of dependencies is just one of the forms of overengineering. Some engineering teams even do their planning and features because of the new shiny thing.

The problem of dependencies is massive these days, and most companies are focusing on producing more and more code instead of helping people manage what they already have.