It's just not reasonable to claim that it's not centralized because theoretically anybody can fork it and do whatever they want while at the same time saying don't do that because it's too dangerous!
Those who control the github keys of the most popular fork (bitcoin/bitcoin) determine the code run by the majority, this however is just common sense. Those who achive and maintain consensus and trust of people have power.
Those who know the beast called "Nakamoto consensus" are quick to point out the dangers, that are very real.
You are still free to fork or rewrite for your own benefit or loss. There are safer ways to play that too, keep asking and listening.