If you buy 1 bitcoin right now, you will likely be rich in 10 years.
Wrong.
The assumption that there will only be 21 million BTC everyone wants doesn't take into account alt-coins.
People will use altcoins when BTC gets too scarce, and it will not be difficult for vendors who accept btc to accept other coins.
The scarcity of btc in the future does not mean what some speculators think it means.
It does not mean the value of a bitcoin will skyrocket. Rather, there will be something else supplying the demand.
In the early 1900s people used pennies for every day purchases.
They were not looking for alternatives because there were so few dollars in circulation.
The early 1900s prices of "shave and a haircut, 2 bits (1 quarter)" is the future bitcoin "shave and a haircut, 2 millibits".