Life contains suffering for any species, that doesn't mean suffering is the purpose. It's just a consequence of it, like getting wet from standing in the rain. While people have debated the purpose for decades, and I'm generally under the 'the purpose is to choose and carry out purpose,, some of the current research on what most people think makes a good life includes: choosing and having meaning in life, mentally rich and interesting, and pleasure alongside (preferably greater than) the pain. For some, children are part of all of these, some - with and without children - work towards those in other ways.
I don't see the benefit in being angry at my parents for my existing or wishing I hadn't been born. Part of coping with trauma is accepting reality and move past wishing it away. I grew up knowing I was a daughter unwanted by my mother, told from my earliest days that I only exist because abortion wasn't accessible or acceptable. Generally I take the neutral idea that there is nothing I can ever do to make up to my mother what was done to her, and there is nothing she can do to make up what was done to me. Non-existence isn't automatically worse than existence, but people who go on that we shouldn't exist because 'humans are bad' and that to think anything good can come from us is 'fantasy' just remind me of my mother who used to say I should kill myself to unburden everyone and to not do so just proved I didn't have real feelings. I learned to tune out such extreme views young.
Humans will eventually go extinct, but I don't get saying 'what makes our species so special' and then listing off special-if-terrible things some humans have done as if cruelty and destruction for destruction sake exists in no other species. Just because they're less capable of it doesn't make us special. We can go on about how terrible we are, self-flagellating dramatically, or we can get on with our unchosen existence by choosing to use our capabilities until the end.
On a objective-ish access to resources level, I have not yet reached the quality of life my parents had at my age, and I likely never will be able to have the quality of life my father has now working in finance and tech. This is partially by circumstances and partially by choice. My mother doesn't have the quality of life her parents had, partially by circumstances and partially by choice and this was true of far more of her generation than I think is commonly talked about. My grandparents were mostly okay for their time, but the relatives I know beyond them were all born subsistence farmers, many of them traveling thousands of miles just as I did but under far worse conditions.
My quality of life is better than theirs, and likely so will my children's which was my great-grandmother's desire when she got out. I'm not trying to compete with my parents, I do not view them as a standard, but looking at my family line, quality of life has meant a lot of different things for my great-grandmother, it was never having to grow her own food or kill a chicken with her own hands again, some people today think that's the height of a quality life and the wider socially incentivized ideas of what a quality life is are going to continue to change. I don't think any one person's kid is going to save the world, but we'll have to go through the population bulge one way or the other and far more of our overpopulation issues are in increased longevity rather than birth end which is already below replacement in the UK and several others parts of the world and heading that way for the Earth as a whole in 30-40 years.