Why does the belief of future usage of Ether increase its price?

I am a newbie in the space of cryptocurrencies so please keep this in mind :). I am wondering what exactly drives Ether's price up? For example, I understand why people are buying Bitcoin - it is scarce and it is something like a store of value which is superior to gold (imo). So people are buying Bitcoin now because they believe that in the future people will want to buy it as well, and since the supply is limited, the price naturally will go up.

Now with Ether, I am not completely sure why it would go up other than the same reason that Bitcoin is going up - store of value. By my understanding, Ether now has a limited supply and hence people see it as a store of value more than before (please correct me if I'm wrong).

Now imagine that Ether did not have a limited supply (as it was before I think). In this scenario the price would go up because people believe that the usage of Ether on the ethereum platform will increase, but why would this make people believe so? Why would the price go up given it is used more? Since more people will use it and hence more supply leading to increase in price?

This question really extends to any platform native token, so I'm really just trying to understand the "economics" of such tokens, not exactly Ether's particularly.