You and I won't experience it. We're doing lots of things to make the earth uninhabitable-- meaning the end of the world (as it were) is gonna happen.
No matter what we do to optimize our planet'ss lifetime, the astronomy community generally agrees about a definite lifetime for the sun-- roughly 5 billion years. From UniverseToday.com":
https://www.universetoday.com/18847/life-of-the-sun/#:~:text=And%20like%20all%20stars%2C%20it,collapse%20into%20a%20white%20dwarf.
"And like all stars, it has a lifespan, characterized by a formation, main sequence, and eventual death.
"This lifespan began roughly 4.6 billion years ago, and will continue for about another 4.5 – 5.5 billion years, when it will deplete its supply of hydrogen, helium, and collapse into a white dwarf."
We're about halfway through the sun's "stable part" of its lifetime. In some 3.5 billion years, astronomers predict the sun will enlarge, engulfing the inner planets causing the earth to be uninhabitable. So, there is an absolute "end of the world" in store some years down the road (even if we optimize things as musch as possible).
When something untoward happens, we often console ourselves with a phase like "relax, it's not the end of the world". Even when the sun burns up and life extinguishes itself on the Earth, There will still be other goings-on!