If a takedown notice is sent, maybe it is because someone's rights are being infringed, or maybe someone is just trying to censor something they don't like, or

If a takedown notice is sent, maybe it is because someone's rights are being infringed, or maybe someone is just trying to censor something they don't like, or falsely claim authorship. You seem to be assuming that the fact that the notice was sent means that the sender is definitely a victim and the owner of the repository is definitely the perpetrator. Not always. The notice and takedown part of DMCA was a reasonable attempt to address a real problem. The main flaw seems to be that bogus takedown notices are never prosecuted, so there's a lot of abuse.