I do agree it's a problem that there's no apparent grand purpose here. However, at some point that would always have to be the case, I think. Say there is a god who has plans for us, you would still have to explain why his plans for us are what they are, eventually there'll be a layer that is simply foundational and without purpose - "his will is simply what it is without any reason". Personally, other concerns cause me a lot more suffering, like: the inevitability of disease (ageing!!), the possibility (inevitability?) of negative interactions with other people (in my case leading to my arrest - pivotal moment for me that really killed a lot of my positivity about life), and my apparently unending personal struggles with employment, which has meant poverty/dependence on others (which I hate) and ever-looming homelessness.
Other people's lives no doubt differ radically. I won't say life sucks, I'll say MY life has sucked (for ME, I don't care how other people assess it from the outside), and I don't want to see it play out any further, I have contempt for reality at this point.