For one, you don't seem to have any concept of our evolutionary biology. Humans have evolved to be goal-oriented, and we receive happiness for participating in activities that are beneficial to our long-term survival.
Second, you don't seem to understand the predatory nature of our economic system and social media. Modern "comforts" (consumerism) and tech are hijacking those endorphin pathways to make us "happy" while we rot. At the back of our minds we know this, and we try to stop it, but few are meaningfully able to and most spiral into depression and anxiety.
That sounds like something good to you? Naive visions of heaven where you spend eternity doing nothing are actually closer to hell than anything else - even a sloth would go insane after a few months. I can understand our ancestors trying to come up with an end-game that they knew would be unattainable, but you think they actually properly thought it through?
I don't think you've properly thought it through. Navel-gazing is a game for prisoners, not people living their lives.
No, we receive happiness for succeeding in activities that are beneficial to our long-term survival.
For example, I doubt that a prehistoric hunter was very happy after spending three days tramping for miles, burning precious calories, hunting for game but not finding any.
2) I understand very well how misguided many people are about "our economic system", because I lived in ~3 different ones. Our economic system is amazing. Consumerism is great (I say it as a frugal person). The social media is not conceptually different from television, just "better" at the good as well as the bad aspects of the latter.
3) The "naive" vision that is "closer to hell" for you was apparently used to entice masses of people for millennia as the vision of heaven. Nobody seemed to be asking much about striving in heaven until the enlightenment philosophers, comfortable middle-class guys. Why do you think that is?
I actually thought this thru very well. It is natural and fine to want some meaning and goals, but the only reason you pine for "striving" is because you already have comfort. I've heard people close to me say things like, "I don't regret not having hobbies or social life [during that entire decade of my youth]; in fact, I don't recall thinking about that, or the meaning of life, or the future, I was too busy and tired putting food on the table.". Tell someone like about the value of striving. And that is most people, throughout most of the history. I'll take being locked in the TV room over being a "striving" peasant any day.