Why do dApps use novel tokens rather than Ether?

I'm learning about Ethereum, ether, and Blockchain tech in general. I get tokens, but also can't refute that all dApps should use ether as their native tokens. For example, The website and which I'm learning on writes the following:

After learning about Ether and how it functions in the Ethereum network – the natural question to ask is why don’t we simply use Ether to pay for every transaction within those dApps? Why do we need a native currency for them? The answer to that is very simple, as in the real world there are plenty of places where we use a token over traditional money.

It goes on to give an example of buying tokens in an arcade. Sure, I get that arcade tokens are useful but always felt that the utility was more in the sense that if people didn't spend all their tokens they would be incentivized to come back, ideally paying more hard cash to exchange for more tokens, buy more concessions, ETC…

So my question is; what's the technical necessity for a dApp to use a non-eth token?