Others have pointed out that you're asking an incoherent question. I'd like to state that even if you refine it to something like "can modern humans be very happy in a big society" (or whatever you do actually mean), you still have the problem of "compared to what"?

Even if you conclude "the average and median human was happier 10000 years ago", you'll face the (Mere Addition Paradox/ Repugnant Conclusion)[https://en.wikipedia.org/wiki/Mere_addition_paradox]. You'll have to figure out how to compare over 7 billion just-OK lives in big societies against a few tens of million pretty-good lives for hunter-gatherers.