Thank you very much for reading. I don't believe in-efficiency in an economical term is necessarily a bad thing. After all most of the economic decisions in countries like US are economically efficient and that's why they don't have a proper healthcare yet. Even so, to answer your question technically Steem blockchain is not rigid at all and is one of the easiest blockchains in the market to make changes since the number of witnesses are very small compared to other chains and they usually agree with Steemit inc. Any hard-fork you heard about until now is a change in the governance and mechanism of blockchain.