We've mined 17m of the 21m bitcoin already.
In that time bitcoin has gone up 6 million times its original value! That makes no sense at all. Even 1000x - 10000x increase would be rather absurd
Bitcoins price is WAYYYYY TOOO HIGH!!! Only 1% of the world has adopted the coin so far. It makes no sense that the first 1% to adopt (aka miners and HODLers) should get up to a 6 million times return on their money. While someone adopting today would get a one times return. That's simply not feasible. The remaining 99% of the population will not agree to deflate their own purchasing power by 6 million - they will just continue to use Fiat.
That's the biggest problem that will prevent bitcoin from scaling.
https://www.youtube.com/watch?v=F7luAHdv61kHeres a great video from Crypto Daily discussing the problems of bitcoins price
How is it any different to many other things? Diamonds could easily be mined in many countries previously, same as oil or gold, the early adopters made a fortune because they realised the value such things could have. The same can be said for early adopters of the internet.