You can't talk about central banking authorities as a single type of homogenous system. There have been and are many different kinds of central banks over time and across borders. Each are run and incentivised very differently. Each operate with different levels of competency and available data. Each can be motivated radically differently - e.g. some are basically run by the government and are prone to political pressure whereas some are run by relatively independent committees (such as Canada, UK, New Zealand).

But Central Banks have the ability to make a huge difference in the quality of life/standard of living in a country depending on its competency and understanding of the economy. If you take the US as an example and compare the response to the 2 greatest financial crashes in the last century. The Fed in 1923 operated under poor information and took the exact wrong course to mitigate a financial crash by contracting monetary supply. Contrast with the Fed in 2008 to date (despite complaints) - its steps in producing massive quantitative easing was the exactly right thing to do. Given their likely responses, there are many more jobs and more economic output today than would have existed had we swapped the 1923 and 2008 federal reserve - I don't think many economists will disagree on that point.

With a decentralised currency like Bitcoin, my understanding is that monetary factors cannot be controlled. So you'd lose a very important tool when it comes to regulating the economy/applying course corrections over economic cycles.