I guess that's like arguing a Prius Prime isn't electric because even though it has a battery and can drive all electric, it also has a gas engine. :shrug:

But very clearly, Preact has the option of the exact same reactivity primitive and design as Vue, Solid, Qwik, and Svelte

https://preactjs.com/guide/v10/signals/

    > In Preact, when a signal is passed down through a tree as props or context, we're only passing around references to the signal. The signal can be updated without re-rendering any components, since components see the signal and not its value. This lets us skip all of the expensive rendering work and jump immediately to any components in the tree that actually access the signal's .value property.

I'll accept an analogy with a hybrid car. In this analogy, Preact would be a gas car with an additional electric engine bolted on as an afterthought.

But you know, the Prius Prime is a PHEV as in "plug in hybrid electric vehicle"

Oh, I see what you mean now! This sounds like a very good analogy.