This still doesn’t answer why bitcoin will be worth more in the future.
The supply side is known, and it has dwindling to a pretty low rate of increase. 88% of all bitcoin there will ever be are already in circulation.
On the demand side, it's a gradual increase of adoption at multiple levels.
TLDR: rate of supply is known and keeps reducing, rate of demand steadily increases as reaching full adoption is long gradual process (decades).