Robert Greer says that there are three asset superclasses: 

1. Capital Assets are productive & generate value or cash-flow: equities, bonds, or rentable real estate. 
2. Transformable/Consumable Assets: can be consumed one time, transformed into another asset, and their consumption produces economic yield: energy or commodities. 
3. Store-of-Value Assets are scarce, cannot be consumed, just transferred, and their value persists over time and space: gold, currencies, art, or bitcoin. 

How does more activity on top of Ethereum translate into a higher price for ETH?

Today, when you want to transact on Ethereum, you need to use ETH. There are currently around 116 million ETH. More transactions on Ethereum means more demand for ETH which means a higher price.

The Future will see Ether become triple-point money, which means it will be a combination of:

1. Store of Value
2. Consumable Asset: Any time something happens on Ethereum, gas needs to be burned, decreasing the overall supply.
3. Capital Asset. Owning ETH represents a share of the Ethereum network, like owning equity in a company.

Apple's AppStore fees can be seen as rent-seeking and the same can be said about all incumbent-run platforms. 

Ethereum is a true platform: projects that build on top of it are actually financially incentivised to support the value of the underlying tech in order to secure their project.