You’re absolutely right. Part and parcel of their high demand, a limited number of bitcoins are in circulation and this fuels its value. In contrast to fiat currencies, which can be diluted by inflation, the work of Bitcoin can provide a kind of shield against such economical problems. The matter is that holding the assets in Bitcoin instead of fiat or even gold is beneficial for those who are looking for inflation-proofing and long-term, stable investments. What is important to note however is that one should keep abreast and with market fluctuations as they pertain to investments.
Based on my knowledge of simple economics, money or rather a suitable currency is supposed to have some key properties of which one of them is supply. For a currency to be able to appreciate rather than depreciate to inflation over time, it should be of limited availability and supply as this would assist alot in value increment. Bitcoin has this in it's protocol and that is where bitcoin halving has a key role to play in the price of bitcoin. To slower the rate at which new bitcoins are pumped into circulation, the higher the chances of price progression.
On the other hand if mining were to remain fixed and all the coins mined too soon, chances have it that price will likely drop or consolidate a little downwards. Majority of these things including adoption are key factors that keeps bitcoin at the top of all other crypto currencies.