What are the best criticisms of blockchain technology? Specifically, what are the top flaws of the blockchain as it's currently implemented by Bitcoin?
Decentralized technology is inherently more inefficient than centralized tech. In Bitcoin this expresses e.g. in the difficulties to implement Scalability and the Proof of Works energy consumption.
The other most prevalent criticism I've read is that there is no central instance in Bitcoin to dampen value swings. The predetermined rate of money creation does not leave any option of steering the money supply. While this is something many Bitcoin advocates like about the project, citing the patchy performance of central banking in the past, the resulting volatility is frequently listed as the most important design flaw of Bitcoin.