I'm a CHRISTIAN, not a creationist. "Creationism" because the Christian's way of trying to get around the secularist's ban on God in school. Anyway ... I will attempt to answer your question. Just know that it comes from that point of view.
I mock "the science" of carbon dating. You may be aghast by this, but I do. I tell people all the time, look at that rock over there. It may be a billion years old, or 10 million years old, or maybe only 10,000 years old. How do we know? NO ONE KNOWS! Then along comes some brainiac who explains how he "knows." He gives us a bit of scientific mumbo jumbo about carbon half life, etc. and voila! We believe him. But ... if no one was there before that rock came to be, if no one knows how, let alone when, that rock came to be, then how do we know Mr. Carbon Dating is right? You already know that we don't know!
I'll go further ... the "science" of carbon dating is what ... 50 years old? They are basically taking things that they KNOW the age of and measuring the carbon in them. Okay.... I ask a simple question: What if carbon does not break down at a consistent rate over time? What if it doesn't breakdown at a consistent rate at varying temperature, altitudes, climates, etc.? You want scientific FACT? I'll give you logical facts:
No one knows the age of the earth. Christians and Jews have their opinions, based on God's word. Scientiists have their OPINIONS based on their best scientific GUESSES, using the best scientific methods of the day. But carbon dating is not factual. Wait! It MAY BE factual, but it cannot be proved to be! And it's folly to say that we KNOW that this bolder or this fossil or this plant is such and such an age. Pure folly! The science rests as much on knowing that NO ONE knows the right answer as it does on calculating the answers.
So, given what I just said about carbon dating, we can apply such shadows of doubt to almost all of life. How do you know that your parents are indeed your parents? How do you know that you are who you say you are? WHAT IF you were born in Berlin 1 year before you were told that you were to two people who gave you away to "those people" who raised you as their own? What if, indeed! How can you PROVE that you were born to these parents?!
You said, ASSUMING that macro-evolution is true, etc. The fact is that there are MANY things thought to be false that are in fact true. I suspect that you don't believe in God. Does that make Him a lie? Of course not! Whatever percentage of non-believers doesn't change the facts. Either God is real or He is not. It has nothing to do with how many people believe. Yet, evolution has this "following" that slams this theory down our throats. You can't prove it any more than I can prove God is real. I'm good with that! If God Almighty wants me to believe in macro-evolution then He'll reveal it to me. Otherwise, I believe what I believe by some combination of faith, reason, logic, and empirical evidence. That does NOT make the things I believe in factual, at least not always. But trust me, my friend, when I say, lots of "science" isn't factual either. At least, they can't prove that it is.