THIS!!!

This is really the question most of us should be asking, instead of constantly worrying about the price.

But, it is quite hard to measure the success though as. Well at the beginning, from a few dollars to a thousand dollar was definitely a big milestone for BTC and should be accounted in the measure of success. However, from there on the price is not as relevant anymore (perhaps if we can break 20k). 

What is more important are companies / industries applying blockchain tech, the growth of this should also be added as a part of BTC success.
We could look at the price and volume and try to measure the success of BTC through that, but really it would not be a real value of its success as the price and volume is not sustainable and could drop anytime. Its real success should be counted through ppls usage of the blockchain tech.