To earn 100 times, 1000 times, yes, it's too late to buy Bitcoin. But you can still earn 3 times, 5 times in the coming years. After all, there is a saturation point and it cannot experience astronomical increases after a certain point. Bitcoin is now mainstream, Bitcoin price is given together with Dollar, Euro, Gold price in economic news. To get to this point in 16 years is a great achievement. Bitcoin will continue to be a good investment tool, but if you want your money to increase 1000 times in an instant, this is no longer possible with Bitcoin.
If our expectations were limited, then it isn't too late to buy. As said, the market price will gradually move, and there'll be saturation at some point. Beyond which the growth could be really hard. I'm not sure of it, but there are predictions coming out that bitcoin will reach one million and so on. Only time can give the answer. The limited supply is stated as the major reason for the growth for the future. Different countries and corporate networks getting into the accumulation of bitcoin is a reason for the future growth. At the same time, things can go centralized when a certain group of ventures holds a major portion of the mined coins. Right now it is not late for people who think of multiplying through DCA. Also, it has turned out to be a rich person's investment, though it can be invested with very few dollars.