You make a good point - ETF flows do create concentrated pressure on price, and that's worth acknowledging. When billions move in or out through a handful of institutional players, it absolutely shapes short-term volatility. That's real.
But I'd separate "influence over price" from "centralization of bitcoin." These are two different things.
Bitcoin's "no single point of failure" narrative isn't about price stability - it's about the system itself. No single entity can change the rules, reverse a transaction, or shut it down. That remains true whether bitcoin is at 30,000 or 130,000.
ETFs are part of the market layer - how people trade and access bitcoin. But the protocol layer - how bitcoin actually works - doesn't care about ETF flows. If every ETF liquidated tomorrow, the network keeps running block by block, exactly as designed.
So I'd say you're right that centralized influence exists in the market. But that's true of every asset - a handful of firms move oil prices, stock prices, and bond yields too. The difference with bitcoin is that even with all that market influence, nobody can change the underlying rules. And that's what actually matters.