This is unfortunately an axiomatic philosophical disagreement.
For those with my viewpoint, of nothing mattering to you, once you are dead and gone, this is basically unfalsifiable, as are most axiomatic disagreements.
And the quotes and arguments that you link in that video, basically just come off as a nice sounding cope, made by people who are distracting themselves from the horror of the reality of our situation. It is an emotional play, and humans are great at tricking themselves with emotions.
I don't really blame people for that though. My perspective really is pretty terrifying. It makes sense why people would hide from it. And the only way that recognizing it helps me, is that I am informed about fringe technologies, like cryonics, that currently are pretty unlikely to work.
On the other hand I view concerns about the afterlife to actually be somewhat depressing. So much time and energy from the limited time we actually have being spent on some fantasy that is completely unverifiable, and so much of it motivated by fear (of hell, emptiness, a vengeful god, etc).
To state my view point simply: The unknown is scary, concerning oneself with an afterlife (or singularity, life extension, etc) is a coping mechanism to avoid processing that fear, whereas admitting that our existence is finite is an acceptance that there are things we can’t know, can’t prepare for, and that we shouldn’t waste our time on.
All evidence points that this is true so far. What is wrong with that? It doesn't mean life doesn't matter. This passage from Carl Sagan's Pale Blue Dot comes to mind: https://www.youtube.com/watch?v=wupToqz1e2g