If bitcoin will be centralized, the idea of inventing bitcoin will be a waste because bitcoin was discovered or I might say invented for the concept of decentralized. There will be a middleman which is the government that will put their presence by adding transaction fee instead of having the exact amount of the product and/or services you want to avail... The idea of bitcoin is to have the trading by peer-to-peer and there will be no other to act as middleman.