It’s odd, they do seem generally more inclusive and less cliquey, but humans are humans, and that means bullying still happens. The really intense stuff has been empowered by internet anonymity (or short of that, a lack of physical presence and the accompanying repercussions), perfect for your prototypical emotionally damaged coward of a bully.
For those who don’t go nuclear, it seems like the main thing is exclusion, but it can be hard to decide when that moves from them simply associating with the people they want, to passive aggressive bullying. I’m sure the number of people cruelly left off the “new” group text for some bullshit reason is pretty large though.