I was filling the car up a few days ago and thought what it would be like to pay with BTC.
Maybe it will never be illegal in the UK or my government would have said so already but it may never become mainstream and ONLY niche.
The price we dream of for a BTC to be 5 figures is the day my mum has her own BTC account which she takes travelling and she 55 years old. Blockchain is staying but can it force its way into mainstream if given time. Will it happen or NOT. Is the fact that japan have adopted it and they are a developed country means that its ONLY a matter of time the west adopts it.
10-15 years is hard to imagine and so far down the road...
From technical perspective, Bitcoin would have LN and this has to drastically increase the transaction capacity. Instant transactions, low fees, user adoption.
Bitcoins volatility might be stopping some merchants from accepting it, but as bitcoin price increases and user demand for bitcoin as a payment option rises, more merchants would start accepting it, merchant adoption.
I think the biggest barrier that is stopping bitcoin from going mainstream is a good number of people don't understand the technology behind bitcoin or how it works and then there are some misconceptions. It would take some time for people to grasp what is bitcoin/blockchain technology.
Another good number of people even don't know bitcoin exists because they don't have internet access, maybe in the future, Blockstream Satellite will overcome this barrier, global adoption.
I believe in the coming years more countries would legalise bitcoin and it is possible for bitcoin to attain global adoption in the next 10 to 15 years.
According to Andreas Antonopoulos bcoin mainstream adoption will take 15 to 20 years, https://youtu.be/y3cKBDBabtA