Disease often stunts growth and mental development, being orphaned at a young age (like myself and my sister were) was an irredeemable loss that made everything about my life harder and worse.
I've seen countless individuals raise friends and family rounds for ideas I was working on and as a result of my lack of connections or proximity to wealth the growth of my bootstrapped company was slower and worse without capital investment.
Better is better, worse is worse, romanticizing suffering is a form of stockholm syndrome often times, where people just can't come to terms with the fact that their lives are demonstrably worse for the malnourishment they've experienced.
These people arguing that suffering creates growth must have very benign views of suffering or have experienced suffering very limited in scope.
I think many have only experienced personal challenges and conflate it with loss and suffering.
Human psychology seems to think everything is a trade off, it's not true, some things are pure win and pure loss.
Suffering creates a personal internal response, often times a stoic or any psychologically positive response is beneficial to the individual because of its motivating effect (similar to how optimists tend to outperform pessimists), but let's not fool ourselves, the man with severe brain/body damage may do better with an optimistic perspective than pessimistic but they'll never code or procreate again and their local maxima is objectively worse.