

So… That isn’t exactly true. You’re correct that there’s a limit to the total and circulating number of coins, but if the world suddenly decides 1 BTC = US$0, it doesn’t matter if there are less coins tomorrow than today. Both days, each coin is still worth zero.
All that to say, there’s no guarantee that a bitcoin’s value will increase over time.
There is one “inherent use” (if I’m understanding that term correctly) of bitcoin, and that’s to pay for space in blocks. Again, that only gives bitcoin value if people want to use bitcoin, so take that as you will.