Is Pain a Good?
You say that we have agency to prevent pain but this is not a straightforward.
Yes, certainly through choices we make now, such as one's made by government we have can make a difference to ecology and future generations.
But even then, we are not gods and cannot control nature. For example, no one a year ago would have expected Covid_19. Some people put the blame on a laboratory mistake in China, but even then, the virus as a deathly aspect of nature is hard to control. Of course, decisions made by politicians may have not helped but none of the decisions have been clear because the virus once it is spreading is a force of its own and human beings cannot master it. Also, preventing certain people's suffering may be at the cost of other people. For example, lockdowns may prevent deaths for certain vulnerable people but create poverty for others.
Another complication is that physical pain is easier to define than emotional pain. Certain experiences such as abuse and bullying are highly likely to lead to emotional suffering but beyond that emotional pain can be subjective. Two people can be in a group discussion and one person may come away feeling uplifted and another one may feel completely depressed.
So, the problem of pain and suffering is very complex. So, I really can't see how you thought it was a matter for a vote, and what would a majority vote count for. However, I think the issue is a very important area of philosophical discussion.
I would argue that we should do the best we can to prevent all suffering but we can only do this to this. To intentionally create pain for others on the basis of promoting growth through suffering would be dangerous indeed. However, by the very unpredictable nature of life it is inevitable. We may fall apart or be transformed by it and this is a quest, but the creation of pain itself only partially preventable. Utopian attempts be worthwhile to eradicate a fair amount of suffering as humans are complex creatures it is likely that suffering would still exist in some form or another.