Earlier quoted context omitted.
Careful what you wish for. Aging and death are woven deeply into the fabric of society, indeed, into the fabric of life itself. Old growth needs to be periodically swept away to make room for new growth. The only logically possible outcome of immortality is that sooner or later the entire biomass of the planet is consumed by immortals, at which point all growth must stop. Imagine being the last person born into such…
Given technological progress and human nature I think that might be a temporary or worst case scenario but unlikely to be a long term status quo. What about exploration or just plain old boredom? There might be more radical escapes (VR, brain upload), more extreme sports or more people leaving this planet in search of something else. 1000 years is a long time. Forever is a lot longer than that..
This universe does not allow for that (black holes, galaxy collisions, stars burn out, meteorite collisions, accidents, war, crime)
If you stay on earth you have 4 or 5 billion years.
Nevermind the human aspects: 1) having to eat soup forever (teeth won't last that long) 2) marriage is forever (no, not even until death anymore)