Very true blockchain is not ultimate solution for everything. But, Blockchain and cryptocurrencies can be make good impact in technological part on society.
Long term impact should be good. When we see many government have positive movement in digital currency and blockchain, when we see many top bank going accept digital currency, when we see big company and top level currency make partnership each other. so we can hope it, Overall crypto and blockchain can be be positive impact in our society.
Definitely there have many part for improvement in current blockchain technology. Like giant company facebook, google when they start positively think about blockchain although they may start and we can find more good solution through blockchain technology which can be good for us.