It is a design choice to offer a news feed that combines verified news sources with conspiracy blogs — interspersed with photos of a family picnic — with no distinction between these very different types of information. It is a design choice to use algorithms that find the most emotional or outrageous content to show users, hoping it keeps them online. And it is a design choice to send bright red notifications, keeping people in a state of expectation for the next photo or juicy piece of gossip.
Platform design is a silent pilot steering human behavior.
Human can be shitty, but giving the control over to the few shitty people who want to profit off of making the world more shitty is whole lot of worse than people being shitty at one time or another.
It exists in here too but also that’s why it’s the fediverse, you can switch to a less shittyverse.