I think a few counterpoints occur to me. The sort of quick one is that I think you also need to consider fear of the unknown. Even if the bad outweighs the good, the devil you know is better than the devil you don't. Additionally, most cultures have suicide as an immoral act, and many would say it incurs significantly negative consequences in the afterlife. So one might keep living simply to keep in accordance with morality, and/or because as bad as it is, it can always get worse. There's also the sheer biological survival instinct to consider as well.
The other thing is that this seems too personal an approach? If that's the right word? I'm going to try not to get too political with it, but I need an example of mass suffering to make this point, and mass suffering is usually political. In that context the situation at the US border seems a useful example. We have this group of people who's prospects were so bleak they made the difficult trip to come seek refuge in the US. Now they're being detained and held in very poor conditions. Also, they do not currently have the ability to suicide. All that collective suffering certainly outweighs any amount of good in my own life, but I'd never choose to end my life because of that imbalance.
That makes me think that the sum of individuals' choices to continue living is maybe not a great indicator of the balance of good and bad in the world.
Then on a final note, while suicide is kind of a useful thought experiment for this, the reality is different. As an example there, my mother committed suicide shortly after I was born, and it wasn't because she thought the bad in her life outweighed the good. It was because she had a medical condition affecting her mental health that made it impossible for her to evaluate good and bad in her life at that moment. The vast majority of suicides and attempts come from similar medical conditions.
Time flies like the wind,
and fruit flies like a banana.