No mystery here
Coming halving in 2020 is main reason
I have just been reading that during halving time bitcoin can be 1 trillion market cup and price around 55k$
Yet another is bitcoin adoption we have LN and there is more demand from merchants coming
Finally Bakkt will be approved that year and crypto custody services can create more demand from institutional investors
If bitcoin infrastructure will grow than finally SEC will approve ETF and we will have crazy run
Question is what will be after
I agree with you. More than changes in functionality and advertising those things are a lot more important.
Why? Because Bitcoin will advertise itself(specifically people telling other people) when the price is high, so that they will come due to greed. Now the fun part is that some might/will research about Bitcoin and Blockchain and will stay because they also like to principles and the goal we have for the future.