Bitcoin is very volatile, not even from day to day, but sinking much in between the halvings and rising too much around it.
Perhaps the timespan between the reducing of the availibility is to long for humans.
Some even call it a cyclical asset.
Perhaps the guess for the halving time for 4 years was a little bit to long.
For a more stable constant rise and a mature asset perhaps it has to be a shorter period
then nearly half a decade.
The total amount of 21mill coins has never to be touched.