I think that a lot of your perception of reality and your expectations are shaped by the past that you grew up in. Whatever you were taught and shown by your environment will determine what a worthwhile life is to you.
Being a russian peasant from a Russian novel might be miserable if you see it from your modern technological lens, but if you truly were this peasant? You were born in these conditions, you were used to these conditions, this is your life. You took care of animals, took care of crops, you had your routine and meaning in life. You hung out with your neighbors, played folk songs and danced. Your parents and grandparents lived this life, they taught you things about this life. If such a peasant was transported into this modern life, i believe they'd be in a gigantic crisis of meaning, not fit in anywhere, and probably kill themselves :0
Now take a typical user of sanctioned-suicide. Most likely they are plagued by intense meaninglessness, coupled with traumatic experiences that they didn't have the correct social support structures for/that they can't have control over and will plague them whatever they do. What are these people taking care of? They don't see any crops grow, they don't derive pleasure out of taking care of animals (or maybe they do in the case of pets, but of course on a smaller scale than a peasant that takes care of cows, chickens, etc.), they are often lonely. One of the most important components of dignified human life is missing.
If you never had an impression of what a worthwile life could feel like, the only logical choice seems to be suicide for some people. Because what would accepting reality in such a case do? You accept a sad state of being, but what are you dreaming about? Are you taking care of anything besides preparing for suicide? The loss of purpose and meaning is the biggest threat to our will to live it seems like.