A lot of it honestly does depend on usage. I have had several years old aged accounts flagged within the first week doing a scraping operation. Ultimately the secret sauce was basically this: use one proxy IP per account and reuse cookies. Nothing sets off the FB ban algorithm like constantly signing in and out of an account dozens of times per day. Saving and injecting valid, authenticated cookies has kept accounts alive longer than anything else.
That said, I don't have hard numbers on age affecting longevity, when taking the proper precautions as described above. My hunch is age still matters, but honestly proxy IPs and cookies matter far more.