This is the bullish case. Different projections for Bitcoin price to go up to 100,000$ possibly by 2040. In the year 2017, we saw the last all time high (~20,000$). In 2019, we had another peak (~15,000). Due to Corona virus and current economic depression, we will possibly not see great growth until the recession starts to recover. However, all the peaks since the birth of Bitcoin is above the Bitcoin growth curve (yellow line that acts as the supporting base). The thin white lines are Bitcoin logarithmic growth curves which shows exponential growth of Bitcoin price leading to 1 million dollar by that time! However, that is overly optimistic. Bitcoin price is most likely follow the growth patterns shown with the green, red and purple lines. Those lines will reach 100,000$ mark in the year of 2031, 2035, 2038 respectively. And who knows, Bitcoin even can reach a 1 million dollar mark!! These lines may act as support and resistance many many times while keeping the same growth rate over a longer timeframe. This is speculation to persuade new Bitcoin users. Bitcoin only gains as long as it's more used, owned and invested, just like any other assets. The only difference in the case of Bitcoin is that, the growth rate will be much faster as Bitcoin, being decentralized cryptocoin and with a finite supply and with the security provided by the proof of work, is less likely to be manipulated by any entity.
So, what's the bearish case. On the other hand, if people start disbelieving in Bitcoin, or people lose a lot of money because Bitcoin's security get compromised (unlikely!), or all the governments of all the countries decide to stop internet to block Bitcoin (unlikely!), or ban cryptocurrency exchanges or make them illegal like in some countries (likely!), or jail many many people for owning Bitcoin via fear mongering (unlikely!), or some other reasons for why speculators may lose interest, or some other crypto currency will reign over Bitcoin, Bitcoin price will not go as high as mentioned above(unlikely!). But, I believe it will still remain valuable (will stay above around the yellow line, maintaining around 20K price). Bitcoin will find itself in human history for a great experiment, no matter what.
But, why not taking the bet?
I am accumulating as many as possible. But when you invest, but we should also learn to diversify portfolio to spread the risk. Let's say you have 1000 dollar, then put 50$ (5% of 1000$) at least in Bitcoin, and then the rest you can put in valuable company stocks, real estates or whatever else is your favorite. I'm more inclined to put more!
Let's be the rational bitcoiner. There is only 21 million bitcoin, if you own 1 bitcoin you will get into the 21 million bitcoiner club, if you own 21 bitcoin you will get into the 1 million bitcoiner club.