The most urgent need for bitcoin is the high rate of small transactions, which will greatly restrict the development of the community.
Bitcoin and other cryptos are big game changer in the field of financial system. It was made to modernize our way of trading currencies/coins. It was made to make our payment system to become more convenient and more organized and alos to make our coins/currencies to become decentralized. I think the only thing that bitcoin or blockchain must improve is the cost of transactions that can be done by blockchain.