alphaXiv (https://alphaxiv.org/) is a discussion layer on top of arXiv, and it's starting to gain a lot of traction.
You can replace the arXiv URL with "alphaXiv" to get to the discussion: https://arxiv.org/abs/2404.16710 → https://alphaxiv.org/abs/2404.16710
Disclaimer: I'm currently helping out with alphaXiv -- it's a fun project out of Stanford