Is their life really "ended" if there is still an infinite number of them in other timelines? I'm kind-of joking, but once you start contemplating the multiverse things stop making much sense.

It's not made super clear but it seems the TVA does not destroy every branching timeline. By extension we can arguably infer that infinite copies of "everybody" still exist, just in a smaller set of timelines (the ones the TVA allows to exist). So, if they've erased an infinite amount of life, but also an infinite amount of life still exists, then what actually happened?