The dragons are an interesting theory for sure, but personally I find the former existence of giant lizards easier to believe than that of giant lizards who also breathe fire.
So as dragonkin I'd like to clear up something here. Manaketes generally don't share this information with humans, as most of us like to watch and laugh as humans argue over this but: dragons and dinosaurs share a common ancestor in the same way that humans and apes do, some "dinosaur" bones found over the years may have indeed been dragon bones instead. Millions of years ago we used to live together, sort of like how there were initially a few different "human" species alive at the same time. However, the dinosaurs eventually came to grow jealous of our ability to fly and breathe various elements and our longevity and so decided to wage war on us. As you can see, they lost that war. That impact crater near the Yucatan Peninsula was not actually caused by a meteor impact, but was rather the site of the final battle where Naga II crushed the last of the dinosaur military and finally ended the war. It was rather long and bloody--the dinosaurs insisted on fighting to the last 'saur--so the war caused their extinction.
.....ok so now that i'm done shitposting, I'll address a few actual things:
First thing is that it is indeed true that radiocarbon dating only allows for accurate dating in the tens of thousands of years range. As I understand it, radioisotope dating basically works via the half-life of the element (or more specifically, the particular isotope of the element being used). Carbon-14 (which is iirc the isotope used in radiocarbon dating) has a half-life of something like ~6000 years. So there's only so far back that you can go for dating with radiocarbon dating. The thing you're trying to date also has to have carbon in it.
In geology, other elements are used for the radioisotope dating of rocks, such as rubidium and strontium. These elements have way longer half-lives (on like the order of millions of years) and so are used for dating of rocks instead of carbon. You don't necessarily have to test the fossil itself, as it should be the same age as the rock itself. There's limitations to this however, as you can only radioisotope date igneous rocks. Sedimentary and metamorphic rocks are formed from older rocks and so will not likely give you an accurate age.
In order to say that the age of the Earth is different than we currently think it is and that geologic history is not on the scale of time we currently think it is, there would need to be discovered some sort of fundamental flaw in our understanding and use of radioisotope dating or something. And whatever other methods we might use for absolute dating, I don't know if there's others besides radioisotope.
There's also relative dating, in which you can get a general idea of what's older and what's younger than each other just by looking at it, but not assign numbers.
The next thing to point out would be that evolution does not deal with the origin of life on planet Earth at all; it merely gives an explanation for the changes in the fossil record (which is not really something that's misunderstood or faked) we see. It deals with life after it began on the planet. And when the world's had billions of years to change, it's not so crazy to think that any sort of life form we've seen so far could exist and sort of descend from one another. You throw darts at a dartboard long enough, and you'll eventually hit the bullseye. Keep making minute changes to something (or significant changes every once in a blue moon), and after a long enough time, it'll be way different from what you started with.
But that's also probably part of why some people have difficulty accepting the idea. To something as short-lived as a human, millions or billions of years can be immensely difficult to fathom. But there's some examples of evolution occurring in a much shorter span of time. Look at dogs or antibiotic resistances in bacteria. Those aren't perfect examples, but I thought I'd throw them out there.