Helpful thoughts, I feel motivated to spend less time looking at comment sections.

I wonder, would the following be some reasons that weigh in the opposite direction? First, looking at comment sections is a way to learn which arguments are popular. This knowledge would be helpful if one wanted to think through how to respond to popular, bad arguments from the other side that one is likely to encounter. Second, looking at terrible comments made by people on one's own side can help one be more patient when one is on the receiving end of rude comments from someone on the other side. I find it easier to be patient with pro-choicers being rude to me when I reflect on the fact that they have seen awful comments from pro-lifers and have likely been on the receiving end of pro-lifers' rude treatment. And third (and most speculatively), maybe engaging people in toxic comment sections is a way to develop a thicker skin. I would think that one way to become less uncomfortable with being treated rudely would be to get used to it by repeatedly being treated rudely.