There are plenty of good arguments for requiring people to use their actual identities on social media. You may think the downsides outweigh the advantages, but it’s absurd to say there is “no legitimate reason”
There is no good argument for making it a *requirement*. If the platform has issues moderating its content, then there are solutions other than requiring their users to identify themselves. Plus, as we saw, asking for ID does not help fight against problematic content and its spread. The root of the problem may lie elsewhere, e.g. in the system which boosts user-generated content which draws clicks (clickbait) and likes (outrage and fake news). Asking for ID is only good for the targetted advertisement business, telling otherwise is a decoy.