You don't know why fossils exist. You don't know if there was a rogue dwarf planet that caused a global event, or a binary system that wreaked upheval on the surface and living creatures. You don't know if "the gods" caused fossilized remains to exist when they destroyed things. You don't know if fossils have "apparent ages" that make them seem older than they actually are - through radiological, chemical, biological or epidemiological reasons.
Academia ASSUMES fossils are remains from a very long time ago. They use their dating methods - which are not perfect and measurably erroneous - to further substantiate their claims. But, that also assumes that isotopes in biological entities do not undergo spontaneous radioactivity (which can, in fact, happen,) aging the remains.
The fossil theory is desperately necessary for the evolution FACT - and FACT is truth, or its own entity? Carbon dating goes up to 75,000 years, but loses accuracy long before that point.
Carbon 14 was doubled due to our nuclear testing age, so if someone comes and collects our fossils some centuries from now, they wont have an accurate measure to date - or rather, the dating will be in error. How do we know a similar event did not happen for the samples we gathered? We dont.
So, you have to ignore many, many things in order to assume the things about evolution. It is a great academic track of a theory, since you need infinite time for some of the things it suggest to naturally happen - and 3 billion years is a while enogh.
This is why if you start with error, but ignore that starting with error will pollute operations over that error, then everything else works out. Core and Carbon dating methods assume, extrapolate and account for inconsistencies based on what is assume should be.
So, if scientists claim it is FACT, they should either add a caveat, or stop saying it is FACT.