2017 was when retail users adopted Bitcoin. Institutions are governments were against it. Bitcoin moved from $1K to $20K
2020/21 is when institutions are adopting Bitcoin. If 10% of cash held by Fortune 500 gets converted to BTC, it's price will be $300K.
And in the next cycle, in 2024/25, governments will realize the importance of Bitcoin. Central bank reserves will have bitcoins in it. This is when we will hit $1M.
Are you sure that every after 3-4 years there is a huge changes in bitcoins value like what happened now? What you think is ] far from the reality that bitcoin will reach 1M, only time and bitcoin market can tell. It's difficult to predict because bitcoin is volatile.