I know, right? It’s fascinating stuff, and medicine (and the technologies that underlie it) will be much more advanced in 20 years than it is today. But the same was true 20 years ago. And 20 years before that. There’s always exciting new cutting edge developments in drugs and techniques and treatments and our knowledge of the body. Which have generally increased human lifespan, but at a relatively modest rate.
Of the things you mention, I think only the potential for genetic modification has any real chance of a marked increase in human lifespan. Organ development and related technologies are wonderful, and will vastly increase the lifespan of young people who currently lack available transplants - but their utility in increasing overall lifespan is very limited, constrained by the physical process of performing transplants. Surgery is traumatic and dangerous. We’re not going to be performing surgeries on healthy older people to replace a healthy 50 year old heart with a brand new one, because the process of performing that surgery is really chancy - and as the years roll on, it gets more and more dangerous and difficult.
As for genetics, it certainly shows potential in giving people protections against the sorts of things that will kill them before they reach very late life - cancer, heart disease, and the like. But even people that dodge every single bullet throughout their life and make it to close to the century mark without those things killing them will die within a decade or two. Without fail. In a huge population sample (in the billions), the people who have the very best genes and the best possible life path for longevity don’t make it past 110 in any great numbers. That leaves a lot of potential life expectancy for the population (getting more people closer to that 110 instead of dying of things in their 50’s or 70’s or so), but not a lot of optimism for using gene therapy to extend the outer bounds of longevity. Especially since so few other animals are able to avoid senescence outright - and none of them have metabolisms or biology similar to ours.
I’m about as far from a biologist as one can be, but from a layperson’s perspective it certainly doesn’t seem like the general condition of aging can be solved with genetic modification. Genetics might allow us to eliminate many - heck, maybe all - of the specific things that will kill you before you get to the theoretical limit of longevity caused by things just being too old to work. Give everyone the optimal genetic code for longevity. But it seems pretty unlikely that the best possible genetic code let the longest-living humans live that much longer than the longest humans have ever lived.