Levels of carbon-14 become difficult to measure and compare after about 50,000 years (between 8 and 9 half lives; where 1% of the original carbon-14 would remain undecayed).
All dating methods that support this theory are embraced, while any evidence to the contrary, e.g. Prior to radiometric dating, evolution scientists used index fossils a.k.a. A paleontologist would take the discovered fossil to a geologist who would ask the paleontologist what other fossils (searching for an index fossil) were found near their discovery.
Once our geologist had the “index fossil” that was found approximately in the same layer as the newly discovered fossil, he would then see where in the geologic column it came from and presto, he now had a date for his newly discovered fossil.
He would simply go to a chart that listed the geologic column by ‘ages’ and find the place where the index fossil appears, and thereby the geologists could tell the paleontologist how old his fossil was.
Knowledge of radioactivity helps them understand how rocks can be dated, which helps them appreciate the scale of geologic time…
Scientific evidence indicates that some rock layers are several billion years old.