There is no guarantee that you will make a profit by investing in Bitcoin. The Bitcoin market is very volatile, there is never a guarantee that you will make a 100% profit by investing in Bitcoin. But the risk in long-term investment is much lower than in short-term investment. No one is ever able to predict, all we can do is guess.
I disagree with you if you said that all we do is to guess. If you talk about guessing that means you're indirectly telling us that bitcoin investment is just like that of gambling that we guess correctly most times, while sometimes your guessing may not also work as you expected. Bitcoin is a highly volatile asset no doubt, it may not be suitable for everyone's risk tolerance. Many investors believe that Bitcoin has the potential to appreciate over the long term, making it a good investment for those who are willing to take the risk.
Well he is correct but not for long term investors.