Ouroboros
Coincidentia oppositorum
Not completely true.macro evolution is unobservable.
Here's the thing. We can't observe stars either, or galaxies. The stars we see are hundreds of thousands of years old, the farther away, they're millions of years old. What I mean is that the light you see, it's not the light that is coming from the star right now. The stars we see might not even exist at this moment. They existed in the past, but we don't know if they do now. But we can look at the old light from the stars and make conclusions about their existence.
Same goes for the fossil record. We can't see a macro-evolution of one species to another today. It's not enough time span. But, we can see it in the fossil record. But not only there, we can see how it works genetically right now, and understand why it happened in the past. We can see that it did happen, why it happened is what the theory is about.
Air. Oxygen. Gases. Gravity. You can't see gravity. You can see the effects of gravity, but you can't see gravity itself. You can test things you can't see and observe, but even so, macroevolution can be observed in the fossil record, and that's why scientists are trying to figure out why and how.If you cant observe something you cant' test it and therefore you can't prove it.
The whole science of biological/physical evolution started with the discoveries of the strata and fossils. It was because the changes of species in the fossil record could be observed that the whole field of research started. Not the other way around. It wasn't like "let's invent evolution and macroevolution. We have no evidence, and never will, but now we have this anti-religion science we're going to use!" That's not how it happened at all.
One of the first discoveries was that the history of Earth had multiple catastrophes. Whole species went extinct and new species entered the scene. The whole strata is full of this. We're talking many huge events killing of whole ecological systems and then being replaced by complete new ones, but with species that were just slightly different and obviously (can observe) the closer relationship with an earlier species, but without actually being that same one. This is the problem. This is the observation. The conclusion is that the were modified. Perhaps God is creating constantly by erasing whole species and replacing them with new, similar looking ones? Sure. That was one of the first theories, but that didn't hold up either. And so on...
That macroevolution is true, there's no doubt. The problem is rather "how". And that was partially solved by Watson, Crick, and Wilkins. Which is a different story.
Macroevolution can be observed in the past history, looking at paleontological evidence. Macroevolution also fit the radial distribution of species. Macroevolution also fits in the traces of relationships you can see in genetic code. We can only test it on very small dataset of genetic change, so it will take maybe 50-100 years before we can document the first larger evolutionary changes.So how do you know it happens the way macro-evolution describes when it can't be tested or observed?