Not sure if I would agree to that completely. Free tier is always ripe for abuse so in the beginning for a long time, Github has this requirement that you can only have a public repository if you are a non-paying user. Somewhere down the road when machine learning picked up (everyone was on the band wagon of hoarding the data, datalakes, hadoop, flink were at the top) they relaxed that condition allowing one to have a private repository on the free tier.

They are in a tough spot cause they want to continuously ingest all the data to train their LLMs. Any fork or decentralization at large scale of git is going to impact the training pipeline.