If it were guaranteed that the price of bitcoin would stay the same as it is today, would you still buy it? My guess is, the answer is no. But if its value lies in being a currency, price stability is essential. And if your answer is no, how is it then not just a Ponzi scheme? In other words, everyone is buying it on the hope of someone paying more for it in the future, not to use it as a currency.
No, i won't buy it. I knew bitcoin price will be increase in the future, therefore i bought it.
The earlier adopter of bitcoin are lucky because they bought bitcoin with cheapest price at that time.
For now, we just can buy and wait for it. In general, cryptocurrency price increasing every year.