From my experience as a teacher, I believe that ticktock and instagram are the worst offenders, particularly for young women. The hyper-visuality and ease of consumption of these media sets them apart from platforms which can accommodate actual discussion (such as discord). The very fact that ‘influencer’ is now a profession supports my position.
That being said, I am not of the ‘for gods sake won’t someone think of the children’ brigade. Their goal seems to be to use the vulnerability of young people to control the internet.