I am not at all saying that suffering makes you stronger. Nor am I saying that being suicidal is good. I am saying that sometimes, the condition that leads to being suicidal is temporary and that people afterwards are happy they did not end their life.
I feel that it is good that those people did not end their life. Not because they suffered back then, but because they got to be, and are, happy right now.
To that, I would add that if legal euthanasia were very very low threshold, there is a decent change that some of the above people would have ended their life. And that would be a shame.
My proposed solution is not 'ban euthanasia' that is mis-interpreting my stance.
Instead I think the solution is 'make euthanasia possible under certain conditions'.
I do not know exactly what those conditions are. I do expect any conditions chose will be wrong in certain edge cases. I also expect people will probably try and block euthanasia by strengthening those conditions (as is being done with abortions). That still doesn't mean we should drop all conditions for euthanasia.
The solution does not lie at the extremes but somewhere in the uncomfortable middle. To my mind, euthanasia should be easier than it currently is in the parts of the world I know about. (Mostly this is the Netherlands, and from what little I know about the US probably there as well).
edit: to clarify when I say "forcing someone to live through that can later lead to a fulfilling and happy life" I do not mean that having lived through suffering makes life better. I mean that, having lived at all, sometimes life gets better. Either because of treatment, because conditions around you change, or just dumb luck. Note the 'sometimes' there. Because there are plenty of cases where this is not the case. Similarly, there are probably cases where things do eventually get better, but not enough to be worth going through what someone is currently going through.