Yes. Centralization by banks and "Wall Street" is near. Only if they manage to control network nodes and hashrate as well. With most of the circulating supply in their hands, they will have the leverage they need to "bribe" developers in the path they want Bitcoin to head into. The community must stand strong by preventing these giants from ruining Satoshi's original vision for Bitcoin. Otherwise, BTC will lose.
Thank goodness, most people still hold BTC, so chances of centralization are slim. Let's not forget that centralized exchanges like Coinbase and Binance are the dominant forces of the crypto market. They can manipulate prices and crash the market if they want to. Like you've said, it'll be an interesting war to watch. Let's hope Bitcoin wins in the long run.
As you stated, it is not about people wanting decentralization, it is the developers' decision to stick to decentralization. Just like how ETH transition from hybrid POW-POS to fully POS. I do not think developers will be threatened if a centralized institution owns a majority of Bitcoin, now that Bitcoin has gained its ground. Bitcoin developers had never been threatened when Bitcoin was just a small community and now that Bitcoin has grown too much, why worry about it?
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And one best features of the Bitcoin network is no one has the upper hand when it comes to the network, and miners are too decentralized to be manipulated, bitcoin protocol is decentralized in nature so one needs to work hard to make it centralized but I am sure nodes who are fund of the decentralized network will resist this centralization attempt.