Look at the Solana fiasco a while back where the network went down and required a coordinated restart.
Another centralising power in these "smart" blockchains are the stable coin issuers. In the event of a hard fork^2 Tether and USDC essentially have the power to decide single-handedly decide which chain ends up being the correct one. Why? Because they can't support two chains, the value of the tokens would be split in half. So, for example. Let's say Tether decides that Eth 2.0 is not something they would like to support, they would simply say "We will not redeem any coins on Eth 2.0" and that would be it. The value of the DeFi on that chain would evaporate instantly and no one would use it. The fact that almost no-one talks about this is pretty scary.
^1 Only Bitcoin is actually sufficiently decentralised to withstand large take-over attempts and politics, IMO.
^2 Ethereum hard forks every 6 months by design, by the way