...with only 500K-2M users as per Bitcoin.
Those numbers are overestimates, the real numbers are closer to 50k-200k.
Then that would be more incentive for people to roll up their sleeves and grow the userbase. Bitcoin after all had a peak capitalization of what $18 billion or was it higher?
The commodity characteristics means if any digital currency were to hit 100 million users then it would be probably be worth $Trillions.
For block chain ecosystems this is still the age of first adapter nerds and the situation will remain like that for some time. In that regard the first five year period 2008-2013, aka "the age of bitcoin", has been nothing but amazing.
Bitcoin is just one monetary recepy a lá Austrian School & gold bugs, using already outdated block chain tech, and in that respect the age of bitcoin is over, and probably same goes for all purely PoW system. And this is not about bitcoin - or mere financial speculation (even though much of the hypnotism of dollar images still remain, as above), this about the full potential of block chain to reinvent and rebuild whole global society and it's multitude of various localities on decentralized peer-to-peer basis instead of currently centralized hierarchical pyramid schemes. To disrupt the destruction and to realize genuine global constructive anarchy.
To grow the user base of block chain ecosystems and make it available to averadge joe and my granny, much needs to be done and much is being done. In that respect I can talk about FIMK-project, which I'm personally most familiar with. FIMK is a semilocal and semiglobal coin, third of which will be distributed as "basic income" to identifiable Finnish citizens, and to succeed it is very important not to be and not to even appear as a pump-and-dump. The basic technical challenges of the core system are getting solved (on tech wizard 2.5 generation level), and the next and parallel phase is making the tech not only user friendly but easy and simple to adopt and use for both merchants and buyers in every day life. And as the basic philosophy of FIMK is community instead of speculation, the main interest in FIMK assets has not been to imitate stock market, but to vision and plan use of FIMK based assets for example as local community (city, (eco)village, etc.) currencies. Needless to say, FIMK is ongoing gradual process, and its experience and success can teach us a lot of how to grow user base of block chain ecosystems, and to answer from one part in responsible and creative way to the growing global demand for means of building alternative society to replace this self-destructive one.