Which this was subsequently tested in 2016 when...
> The Ethereum Foundation and a majority of mining power decided to violate the immutability of the blockchain and wind back The DAO — because immutability lasts precisely and only until the big boys lose enough money.
So not only immutability was a complete lie in 2016 with the nonsense of 'Code is law' now with the Merge happening to proof-of-stake, unsurprisingly, centralization and big money ultimately wins.
So expect forks of the Ethereum PoW post DAO to just 'fail' like Ethereum Classic has done over the DAO fork.
Further along Gerard's article about Ethereum becoming a security, I think it looks more clearer that it is going to be the case as soon as 'Staking as a service' proliferates towards many retail investors.
As regulations are being much clearer, coins like Ethereum are going to be treading on a very thin line with the SEC and other regulators and if they are not careful it will land them in trouble like what is happening with Ripple with their XRP coin.