It's too far to predict btc position in 2030. But I think there will be many things happen with BTC from now on till 2030. And I think supply will caped if BTC still survives.
It is a huge time period to talk about it. Many people would think that the price is going to be so high that we would never imagine. This could be a scenario. However, on the other side, there is a possibility for cryptocurrencies to be vanished if governments decide that acquiring bitcoin is illegal and every holder should be sued for that.
They cannot successfully do that for something they dont have control over; the system is so anonymous that it will be very hard to know the owner of a wallet talk less of knowing the owner of a particular coin.
If it was possible, that would have been the easiest to do and when we speak of government, every country have their own government and all government cannot at the same time go against it, some government are benefiting from it while some are not, so conflict of interest will make it impossible to get a united decision against it which will make it impossible to make it vanish.