Bitcoin's future is bright. And I think holding bitcoin for long term is very profitable. As of now, bitcoin keep changing and many people using it for online transaction/cashless and bitcoin can use in many ways and it is easy to use.
I'm just guessing there will be a lot of adoption regarding the technology. This is because the level of trust is increasing. Even though the scalability problem is a drawback, because the transaction process gets slower as there are more users. However, because bitcioin has special value, the price will tend to rise.