what happens if the next 10 years, bitcoin disappeared and worthless?
If it disappears then it just disappears and there is nothing that we can do about it. We will just have to move on with our lives without Bitcoin and go back to your countries currency.
Yeah and may be till then we will be having new currency in market, so we would start investing our money into it,but I think bitcoin will not disappear so easily it will survive for a long time.
What you said is correct even if the bitcoin disappears Their wont be much affect on any market as still Bitcoin is not a main stream of Finance or Currency, so if it fails who ever are against it will come in front and start to give the reasons about the failure.