I don't see bitcoin becoming any part of standard currency - ever.
now blockchain on the other hand is very useful and is getting wider use in the backbone transacting between global players.
I see bitcoin (and all it's many derivatives) being no more than the latest shiny fad but bringing into mainstay play the new <span style="font-size:12px;">(not so new any more, 10 years or so)</span> technology of blockchaining.
I don't see bitcoin or really any digital currency going anywhere. It's only worth what people will pay for it. It's not backed up by any banks or countries, it has no stability, and the market goes from one extreme to the other. It could be worthless at anytime!
It was used in black market for gray/illegal activities. At that time, it was only $400 around 2015. I should put all my money (10k) to buy coins at that time, lol. End up nothing for me! it was biggest chance to get rich, but missed the shot.