The simplest answer I can give at this stage is that alleged radioisotope "dating" is not empirical science by modern scientific research methods which Scientism claims to follow. I encourage you to look further into this.
To elaborate, independent attempts outside of structured university systems to date artifcts, bones or any other material produce wildly-differing results from what I understand.
In any case the nail-in-the-coffin of radioisotope "dating" is this: It is inherently untestable and therefore unscientific. For example, if I plant a tree, record the date it's planted and take a photo, in 20 years' time I can say, this tree is 20 years old because of x y z empirical evidence. Of course by the empirical scientific method there should be other corroborating evidence, such as aerial imagery, other people taking photos of the tree and neighbourhood, etc.
Compare this with the Scientism dogma of radioisotope "dating". Not only does it assume a high level of knowledge of radioisotope composition today and in the past hundred years, they extrapolate - key word there - to thousands, millions, and even hundreds of millions of years. This again is untestable as we have no current test of a certain artifact measured over a period of even say a hundred years and showing change in said artifact (going by the modern discovery of radioactive decay, etc). Maybe in the next few decades and century they can demonstrate said artifact and measure it, but again extrapolating a few hundred to thousands let alone millions of years, is, simply, unscientific.