I think you are correct that most of life is a repetition of boring events. We go through the motions of life out of habit and inertia. In my own experiences, what makes life vibrant and fulfilling is usually precisely what is not
the case: possibilities. Anticipation gives life its color, the expectation of a future metamorphosis keeps us going, even if this future never actually materializes.
For example, I may program and code, with a cup of coffee next to me and earbuds in, listening to some sort of space ambient music or science-fiction music. It really pulls me out of "reality" and into a different one, the world of the what-if
. What if I was on a space-faring vessel, exploring some distant star cluster, away from the political bullshit on Earth, the impending environmental disaster, the rampant suffering and decay? I think people live in this world of the what-if more than actual "reality". They spend more time dreaming than acting, because dreaming doesn't come with limitations. People take drugs to escape reality. They browse social media to escape their responsibilities.
I think, even if we can formulate a coherent philosophical pessimism that denounces "life", phenomenal existence, or whatever, we'll all have "good" days, where the world seems a bit more welcoming than usual. We get seduced into loving the world even if there's that little whisper in the back of our minds reminding us of the antelope being eaten alive in the savanna, the inevitable heat death of the universe or the fact that I didn't study for my exam this coming Wednesday. And I guess I would say that this is just who we are, it's in our nature to do this. It reminds me of Werner Herzog's brief bit about the harmony of the universe, and how he loves the forest even against his better judgment.
Probably a generic rule of thumb of the cosmos would be that it cannot satisfy everyone. For every state of affairs, there's always going to be someone for whom it doesn't quite live up to expectations or requirements. The affirmative attitude marginalizes these people, making it seem as though it is their
fault that they find existence to be faulty.
Part of the Heideggerian care structure is the world, which is defined as the system of purposes and meanings that organizes our activities and our identities and within which things make sense to us. There are ready-at-hand entities (equipment), that have a reference towards-which (work), which is for-the-sake-of-which (a possibility of Dasein's Being), or for-Others, etc. The angst, the anxiety, comes from the moments when we ask for what sake do we ourselves exist and do all the things we do. It's a void of meaninglessness in which the nothing "nihilates" our contextual meaning, our world. Nothing matters anymore, it's all just very ephemeral and pointless.