OP read this. It's a lot of text but it's completely filled with citations and is a great introduction to the current state of cryonics which is the Plan B if technology doesn't allow immortality in your lifetime. Everyone should at least consider this option because a non-zero chance of being revived still beats the absolute 0 odds when you're not doing it.
https://waitbutwhy.com/2016/03/cryonics.html>>11180601Very low but it beats actual death which has 0 chance of bringing you back.
Also the better the technology gets over the years the more likely you are to be revived. So try to live as long as possible since the later you get cryogenically preserved the better the preservation and thus the chance of you being able to be revived in the future.
This is called "Last in, first out".