It's important to understand the difference between easy and simple. It's easy to add complexity, it can sometimes be hard to keep things simple.
But with that in mind, I do agree that a lot of systems are more complex than they need to be. I like to keep things simple.
Of course scalability adds complexity, and sometimes you need that. But you don't always need that, and making things scalable that don't need to be, makes them harder to understand and maintain.