Satoshi did his job, now it's on us that how we treat with the bitcoin? Whenever a person does something new, he is not aware of his results, the same thing happens with Satoshi, I think he knew about the bitcoin, but the bitcoin at a stage today, I confidently say, he wouldn't know about it. Of course, bitcoin is believed as decentralized, and the making of nodes has an impact on all of these. The banking system should be a way for it if we think differently.
Bitcoin has now evolved all over the world and it has gained so much potential in the previous few years, Satoshi must be proud of his work, maybe if he was at this stage, he would do many more things like bitcoin, so we could also take benefits from it. Great people have always some great thinking about new things.
Your suggestion to involve the financial system in Bitcoin's decentralized utopia seems to contradict its core values. Bitcoin resists traditional banking systems, right? Didnt Satoshi carefully instill that principle in its DNA? The pseudo-problem may be: How do we balance Bitcoin's revolutionary, decentralized nature with a need to integrate it with established banking systems without compromising its essential principles?