Emitting half of all bitcoin in just the first 4 years is hardly fair. One would hope for a more Gold like distribution, such as a pure linear emission. This still has a finite soft total supply [1].
[1] https://john-tromp.medium.com/a-case-for-using-soft-total-su...
An infinitely growing cryptocurrency presupposes perpetual economic growth, which requires ever increasing population and resource extraction.
Maybe that's realistic if we start colonizing Mars and mining asteroids, but it's not possible on earth alone.
If limited supply turns out to be an issue, competing currencies can be used to augment supply, it's basically already the case.