We may not be early adopters of Bitcoin, so we have plenty of time to start now, that is to build a portfolio. But those who are just starting out should not think that Bitcoin will make them rich instantly but rather keep in mind that Bitcoin can provide a good hedge against inflation therefore one should not mindlessly fall into temptation. Moreover, even though big investors, institutions, governments, and companies are buying Bitcoin even then it was not overvalued, so the background is different at the present time and it indicates that holding any asset other than Bitcoin is not the best return provider. In this context it can be said that you are right that only Bitcoin investors can become millionaires and billionaires in the future.