I think the most important thing here is to empower people closest to the pain. That is to say, people who are suffering the harm should be the people who define the harm. So instead of just the designers trying to figure out how to make sure that it does no harm to everyone, it is simply not possible. All the unforeseen consequences will harm someone at some point. But what we want is that people do not mitigate against those harms thinking; 'this is just how tech works. Tech just happens to us and we overcome doom scrolling ourselves by using grayscale screens or using a stylus instead of your fingers'. I mean, all these interventions work to mitigate doom scrolling as a harm, somewhat, but it shouldn't be up to the individual people suffering the harm to correct a structural oversight.