I used to think that too. But look at the behaviour. People pass around “numbers on a screen” which don’t really mean much. There’s no significant net bitcoin entering. It’s mainly the same amount of bitcoin just switching hands amongst the same people.
So what’s happening, if we’re being objective, is that people are treating zaps more and more like likes or other reactions.
We need to think about this further. It’s far from an economic model like mining