Bitcoin is Finite no matter how long it takes bitcoin will eventually ran out one day but before that happens a new cryptocurrency will probably emerge that will be able to replace bitcoin. it may not be as good as bitcoin but it will be the one who continue the Bitcoin legacy.
Amused with all the responses here, if you really think that bitcoin will eventually be replaced by another coin then no one in the right might out would invest in anything that will eventually run out 
. Bitcoin is here to stay and nothing is going to replace it and it will not run out of coins, in the beginning some people lost their coins because they were not serious about storing the keys as it has no valuation and that is not the situation now.bitcoin isnt the only coin that people are investing with because there were tons of coins out there and they are not as good as bitcoin but they can still be used for money making purposes in the form of trading or investing and yes bitcoin will soon run out of supply but that does not mean that bitcoin will eventually dissapeared in thin air . there will still be bitcoin that will circulate . people will sell and buy bitcoins again and again and it will be a never ending cycle .
Agree, even if all bitcoin will be mined it will still circulate in the market, in my understanding if we say bitcoin will disappear that means that no one will use and that countries prohibited the use of bitcoin but considering bitcoins popularity these days, I don't think no one will use and also with the price hit $9k, more investors will come out.