In the Middle ages there was a big market in relics of varying classes. Anytime the Pope wanted to bring in a big crowd of pilgrimagers (who paid for the opportunity) and raise funds for this basilica or that refurbishment or when the coffers were running low, some new, never before seen relic would miraculously show up. Some people need signs or tangibles to bolster their faith. Jesus said we are more blessed when we believe without seeing.
I believe God intentionally did away with many things that he knew people would worship rather than Him.
There were competing claims by churches who all claimed to have the same authentic relic! And weird ones, like breast milk from Mary...