"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?"
Someone has to prove that it's transactional, and we can buy things with this. Just imagine we are all buying Bitcoin, and no one is spending, and it has no use in reality. So, what is the point of gathering more and more Bitcoin and no plan to spend it? Some people see Lazslo as an Idiot because he sold 10000 Bitcoin for two large-size pizzas.
If you ask me about his actions, that is a historical transaction also involved in this forum. Look at the price and the market where we are today. If no one traded Bitcoin, we wouldn't be here today.