Mrebo if you haven’t listened to 538’s podcast series on gerrymandering (or read the articles on the site, I think, which yhwx may have already linked to) I think it’s worth your time. It covers the issue from several different angles, touching on both the who and the why.
I read a 538 article that focused on PA, something along the lines of gerrymandering not being so easy to fix. It was a lot to digest, I’ll see about the podcast.