When studying diseases of the brain, there are some dementia cases where a good approach is to modify the environment to be very simple and minimalist so that the brain stays focused and keeps a grip on reality. There is no reason to think that this doesn't also help healthy people.
Linus Torvalds famously works from an empty room with light green walls and a nearly silent computer to enhance his focus. I do similar.
I sometimes see people who are known to be scatterbrained and their work environments are obnoxiously overstimulating. I think to myself, "It is no wonder such a person struggles to grasp difficult concepts and repeatedly fails in their code. The work environment is basically a barrier to their ability to focus."
All of this is to say -- do not overstimulate children. Do not introduce them to low quality content that will rot their brain.