I don't agree with this. Github has existed for years and one of the reasons developers trust it is that they never monetized their "archival" work yet (TBD with all the new Copilot features).
The alternative would be many sites, each one of them with their own DMCA rules.
What would be the better alternative?
Why are you thinking in terms of “sites”? I was imagining something more like a GitTorrent.