Recently logged into my old account, check out the date on this egg

I made an account when the game first launched but deleted it not long after.. 10 years later, I started playing again but on another account when I remembered I already had an account.

I recently managed to log back into the OG account and noticed the eggs and other pokemon I have from the summer of 2016 haha

Is there any benefit or anything to having these older pokemon? Or is it just… cool?