The old addage among pro-lifers is that suicide is "a permanent solution to a temporary problem", so...
To actually address the question though, I view it less as a solution to a problem(s) and more as relinquishing problems and solutions altogether. The human experience can be summed up as finding solutions to problems, which in turn creates more problems, which garners way to more solutions, and so on. An example: you want to own a home, but you can't afford one. A solution to this would be to work more to earn more money; let's say that you do this, and you're able to purchase this home. With this, you have "solved" your original problem (that being home ownership), but now you've created additional problems with that solution. You now have to maintain those hours you were working to purchase that home, as well as having to pay for upkeep and now having to do additional chores to maintain that home. This is what being human is all about, the cycle of problems/solutions.
With suicide, you are getting rid of problems and solutions for yourself entirely. You won't be around to create or perceive additional problems (outside of the aftermath of your death, of course), nor will you be able to provide solutions for any problems. I think you can argue that this in fact is the ultimate solution, but it doesn't necessarily solve anything in and of itself. If you're in debt and you CTB, that debt doesn't resolve itself, it gets passed along to someone else. You simply just are not present for the problem/solution cycle.
I don't know if any of this makes sense, apologies if this comes across as metaphysical nonsense. I just don't think something like this has a clear-cut answer. Maybe the absence of problems and solutions is in itself a solution, I can't really say, but I don't think it's as cut and dry as people might make it out to be.
