If bitcoin price grows 40% a year from now on, that will be 1000 times of present value in 20 years. The price is about $400 by the end of this year, so 1 bitcoin will be worth $0.4 million. If you have 10 bitcoin, you can have comfortable retirement life.
yes we can only speculate but this is good assumption on this
also with few halving this may be true
yet price can be only several thousands but from this point of view its high