A negative impact I think you lightly touched upon but want to further expand upon is how will this affect social change in this country. Like lets imagine we go back and say somehow we as humanity discovery this biological immortality around 1886ish (this is going to be very Americancentric) and again lets abstract this and say its given to everyone even though that is unrealistic. I don't think we as a society would have made much progress in terms of rights for women and minorities if we had the lead weight of these god damn fossils outdated view points (their children sort of prove that with the whole bullshit of the daughters of the confederacy and the impact they had in the last 100 years). Hell that is a problem even in the modern world, where our politicians are ancient people in their bloody 50-70s, like congress' median age is 58, some of the most active voters are also the elderly. So we see this problem in the current world and it will only get worse if people had immortality. This doesn't even talk about the idea of the impact this will have on the economy, the idea of retiring is already a foreign concept to many people in this modern world and once again this problem gets worse with immortality since you are literally going to be forced to work till you die.
Like immortality is cool as a concept when its only given to you and a few people you want to select but it gets bloody messy once its a thing that can be handed out willy nilly. It can apply to many concepts like the idea that humans no longer have to sleep, bloody awesome when its only a select few people but once its the norm and seen as the standard it will affect so many different aspects of life. "Well you don't have to sleep Johnson so work for 16 hours or you will get shitcanned because I will find someone who will!".
Nepenthe