It's really a deep question which necessitates a rather complex answer, as it could take different paths.
If biotechnology is the path, then it may mean growing new organs and replacing them as needed (And they will inevitably be needed). However, this would mean multiple surgeries and possible scars everywhere, unless our tissues can be regenerated as well. Even so, sooner or later an organ would fail without warning, and you wouldn't get the transplant in time. In addition, one may get tired of the surgeries and recovery.
It's also theoretically possible that nanobots could be constantly circulating in our blood and repair any damage that needs it. As to who or what repairs the nanobots when they run amok or need repairs, or even how to find the wayward soldier is anyone's guess. It's also very possible your immune system won't roll out the welcome mat for them, which would mean taking immunosuppressive drugs forever, and who wants an immune system that's always on vacation.
Another possibility is the (again theoretical) download of our consciousness into an android body, which frankly my dear, is poppycock in my opinion. We have around 100 billion neurons in our brain (Although we've all met a few where you could leave off the billion part), and each neuron synapse has connections numbering in the thousands, which translates to an astronomical number in the vicinity of 100 trillion connections (Not to mention that they are constantly in flux with each day). So it seems to me this is a pipe dream.
Nevertheless, even if it were possible, it begs the question: "Would it still be you?" There is an age old philosophical thought puzzle in reference to Theseus's ship. The gist of it is that if you take an old ship, and replace the old rotting boards one by one until they are all new, is it still the same ship, or a different one. So, to extract the general essence of that argument, if you could take all your consciousness and put it into a different body, would it still be you?
Imagine putting you consciousness into a different body. Would it feel like you anymore? We seldom think about it, but our body and mind are as intimately connected (They are one), so much so, that even ones who have suffered an amputation still feel like it's there.
There is also the problem of losing the very experiences that comprise our humanity and happiness. Living in an android body means never enjoying a good meal, or sipping a cocktail in a hot tub, or kissing, or making love. That, and so much more would fall by the wayside in exchange for immortality. I'm not sure that would be a good trade-off.
All-in-all, I think becoming immortal (Which, in some fashion, may happen), will bring about a change in our humanity that will be a big price to pay. Our connection to nature will change if we are in an android body (No need to breathe in fresh air, or even care about air pollution). There is also something about having a limited life span that makes life precious. If you could live forever, then life isn't sacred anymore.
There is much more to consider, such as, if you even lived to 150, than means probably working for 80 years just to have enough soc sec and investments to support you for another 50 years. Do you really want to work for 80 years? Perhaps we will live in a post-capitalistic society, and from what I know of humans, getting them to agree to that idealistic way of life will be a fool's errand.
Anyway, enough of my brain wanderings. I do think life spans will increase, and I do think AI will augment society, and I think competing with augmented humans will bring about a structural earthquake in society, but how it will shake out is anyone's guess.