Price of ether

In many occasions I have wondered about factors determining the price of ethereum. I think it is a matter of demand and offer, as almost the price of everything is. Scarcity is important. But how does the demand created? It's a gas for running dapps. So fuel consumption for used dapps on the nerwork and difficulty of validating transactions (cf. Mining), mainly drives the price. However, here comes my question: the goal of the developers of ethereum is to make it more and more efficient, faster, etc. In this way, it will be less "costly" for validating the transactions, which would reduce the fees and fuel consumption of dapps significantly so that the price would be pushed down? In the end scarcity is determined by how much of a fraction of one unit of eth you need to get things done. I am curious about your opinion. Cheers.