A surprise benefit may be finding out which members of the human race are actually immortal and have been hiding it from the rest of society. /s
https://www.popdust.com/conspiracy-theory-thursday-keanu-ree...
https://www.popdust.com/conspiracy-theory-thursday-keanu-ree...
It's even getting to be the case now that you can't just move to a new country and start over. Unless you've got skilled forgers close at hand, you're going to have a bad time immediately, and with facial recognition and biometrics, you'll have a worse time still.
It's perhaps the definition of a low-probability corner case, but if any alchemists happened to succeed, they're no doubt having a pretty depressing century.
This is how the immortals from Ilaria Corporation handled it in Helix. The show was promising, it's really sad it quickly went from interesting to crazy to utter gross.