What are you comparing. A hunter-gather who is starving because there is not enough food would be happier in modern days where nearly everybody has enough food. Likewise a hunter-gather who is in pain for something that is easily treatable.

However when things are going well for the hunter-gather they did have a lot of leisure time and so they could well be happier overall even though the lows were worse.

That doesn't make sense. A hunter-gatherer would have to trade their entire lifestyle for the modern world. And it isn't clear to me that the relief he or she would feel would be worth the entire destruction of their way of life. In fact, I believe it would not be, especially for the many more than aren't hungry or in pain.

Personally, I would trade the lows if I could live in a world where most technology did not exist (that would mean in particular, I could drink from any stream or relax without hearing an ICE.) And no, that does not mean going off into the woods now, where the experience would be vastly different, being surrounded by advanced society.

When you are not hungry or in pain it is easy to say you would make that trade.

There are places in the world where you can get away. there are still hunter-gather tribes around, and some of them would welcome outsiders to join. (some will kill you on sight) You can also buy land in middle of nowhere Alaska (or Montana) where effectively there is no civilization in anywhere close. I'm not sure what country you live in, but odds are there are options where you can just disappear for civilization if you really wanted. While you can get to civilization from the above if you want, it wouldn't be hard to avoid it.

You might ignore other aspects of life. A good part of the children dying before reaching 10 years old (and not only). People not knowing why things happen and worrying is a vengeful god or spirit, or living in fear of the village shaman.

Not sure why you say going to the woods now is not an option. There are enough people choosing to do similar things (ex: Amish style of people). Nowadays we have more options in terms of life style than at any point in history (not without some tradeoffs, but still). You have to make a choice and make your peace with it, don't think it's productive wishing you would not have the options...