I was thinking of making a similar thread, but since this thread is here, I'll just give my two cents. I think, from an objective viewpoint (the universe is pointless and meaning in life is only assumed and prescribed by the sentient beings that give it such meaning and value, aka 'humans'), yes, there are positives. Also since I believe in pro-choice/right to die (on one's own terms), I believe that if one is able to exit on their own terms, they should be able to choose it freely to avoid future potential suffering and generally more bad events (which amplify in severity as one ages, into middle age, twilight years - assuming other causes haven't already happened in the decades prior to that).
I also agree with @Forever Sleep perspective about a potential positive of CTB'ing, being that one takes out oneself before they cause harm to others, and ironically, many pro-lifers (as she mentioned) naively and ignorantly believe that the broken and suicidal can be 'fixed' or do everything to fix that while ignoring that (until something does happen and it becomes a headline/news story, then they criticize and condemn the perpetrator for their actions... So yes, that is a good perspective and also the quote "Die a hero or live long enough to see yourself become the villain," from -Harvey Dent in the Batman movies and such, it really made sense and agreed with that. At least that is how I see people who have CTB'd or so on their own terms, prior to (potential) harm to others. In a weird and cynical sense, they kind of 'saved the world' and I personally think pro-lifers should be grateful, but they would instead go about their entire CTB prevention advocacy and spiel.
Anyways, ultimately, I see it in our own best interests to leave sentience as soon as we see fit, be it young, middle aged, or elderly, as long as one isn't enjoying sentience or life, then that would be a strong sign to leave before nature and/or other causes take it's course.