1. The lack of authority from the crypto founder to resolve issues from its user. We will not talk about the authority coming from the government because many of us here will not agree of them to interfere in the system because they can just ruin the anonymity by conducting KYC and other preventive measures. So, what I am seeing is the lack of addressing problems from the founder of the crypto. After they implemented the system they will just say that system is good and ready to go and if you as a user will get mistake then that is your problem and your fault. No one had force you to join in cryptocurrency and you must adapt to it. This is not good for those who wishes a better system.
The main purpose of any decentralized system is to remove middlemen, decision-makers, and others with the power to make decisions. If there is any authority, then the system cannot be considered decentralized. So, your very argument doesn't make sense since the system you are talking about and proposing is not only not absolutely decentralized, it is not decentralized whatsoever. Bitcoin is so far the only representative of a decentralized monetary network. Even if its founder were to appear again, he would not have power over his own invention.