> Yes my car is running all night while it stands in front of my house, but it's not really a waste of resources or a nuisance because generators do the same thing.

Your analogy is wrong. The rendering engine is the generator.

You know nothing about software if you really think this.

He's right - the DOM also has observers.

The difference is what is rendered, not that observers are involved and the concept of looping.

Millions use React - you want to talk about performance?

It's mining Bitcoin!