the fact that immortality will be found - Reyep
If we consider that technology is constantly evolving and the basic logic of living organisms has remained the same for millions of years, immortality will be found after sufficient time and budget are spent.

The developments that have taken place so far are the production of organs in 3D printers, the production of mechanical limbs, the production of various oraganic organs, inventions in gene technology. Add inventions on stem cell anti-aging technology. A budget and time that thoroughly blends the work in all these areas is something that the owner will eventually complete this task.

It may even have been found now and is still being worked on. If our cells continue to renew themselves, this will happen.