Decentralization is the major crime of Bitcoin against the government and the powers that be. Many efforts are being put to ensure regulation to enable government take absolute control of everything, depending if people will comply or find a way around it.
By design, Bitcoin cannot loose decentralization, however, access to and usage of Bitcoin can be contrained to follow centralization with limited options available should there be full regulation like I explained before.
Many things that people are looking up to such as the Bitcoin ETF might make Bitcoin less decentralized.
It is true that decentralization nature of Bitcoin is a challenge for the governments worldwide, as it undermines the role of central banks in controlling the population through the manipulation of money supply. Therefore, it is obvious that governments will do all what they can to diminish the influence of Bitcoin in the global financial system. I am also afraid that participation of big institutions in Bitcoin via ETFs could jeopardize its decentralization, potentially concentrating the ownership of Bitcoin in few hands. This also raised concerns about market manipulation.