"Why haven't the earliest participants sold their Bitcoin, and some haven't even touched the coins in their addresses, considering the high price of Bitcoin?"
Those who hold these addresses may all be believers
Well, some of them must be, but that isn't the only reason why the coins in all the early addresses haven't moved. Most of them must have abandoned their wallets and lost access to them because they didn't expect Bitcoin to become this much popular, and some might have passed away while holding and the remaining ones are the ones who are still holding their coins till the date and didn't even sell when the price touched $69k in 2021.
I believe that Satoshi still exists, just for an ID, Satoshi can come out again to create a new Bitcoin? Or give me a little bitcoin, and I'll change my life
We can't know if he is still alive or not because no one has ever known him and there has never been any updates about him and his whereabouts. However, even if he shows up, he doesn't need to create or generate new Bitcoins just to make the existing coins lose value which wouldn't make sense because the supply is enough. There are other issues that he can deal with like the scalability and high transaction fees from time to time.