satoshi NEVER worked on bitcoin core.
Correct, satoshi released the original software, which was simply called Bitcoin.
.. core is a brand that came about by colluding devs in 2014 creating the brand in 2014, long after satoshis disappearance
also one dev of core can leave without causing big effect. but if all the colluding devs messed up or left, then there would be issues as its the sole 'reference client' for upgrades and protocol changes.. thus would affect 99% of everyone should an issue arise. and yes core are centralised once you look at the devs funding background and their colleague/partnership interactions. they do not act as independent devs, but a collective
There's at least 4 other independent Bitcoin clients that do not create a fork that could be used instead:
https://github.com/bitcoinknots/bitcoinhttps://github.com/btcsuite/btcdhttps://github.com/libbitcoin/libbitcoin-nodehttps://github.com/bitcoinj/bitcoinj