It is super difficult to have a successful project that is genuinely decentralised.

The the founding entity needs to disappear (BTC) or be forcibly removed by a decentralised community (Hive).

Very few projects have achieved this. Even Ethereum is substantially controlled by a single person (Vitalik) and a single entity (Ethereum Foundation).

It is fortunate that Vitalik is such a great guy and genuinely committed to decentralisation. But he would really need to disappear for the decentralisation of Ethereum to be complete.

The Swiss Foundation model he pioneered works OK but has a lot of problems and the Foundation continues to have huge power in most such blockchains.

Companies as blockchain founders are much worse than the Swiss foundation model because they have their own interests which diverge from the best interests of the blockchain over time.