Actually, BTC is not as centralized as it seems.

Mining pools, exchanges, ETF institutions, governments, and large holders are the major forces.

Firstly, mining pools are a few oligarchs, no need to elaborate.

Secondly, exchanges are also a few oligarchs, with Asia's OKEx, Bitget, Huobi, Korea's Upbit, and America's Coinbase, Kraken... and Binance globally...

Thirdly, ETFs are actually also a few oligarchs because issuing institutions like BlackRock do not participate in the market; the participating market agents are the APs. There are a few ETF issuing institutions like BlackRock, Fidelity, Grayscale... and each issuing institution has several APs participating in the market.

Furthermore, governments, not only the U.S. government, but also the Chinese government hold a significant amount of BTC.

Finally, some retail large holders who entered the market early also hold a large amount of coins.

So overall, Bitcoin is definitely not in a state of perfect competition or complete monopoly. I tend to believe that the BTC market lies between oligopoly and monopolistic competition.