ALL of the experts who study our stone age ancestors report the same things, that their lives were hard, dangerous, and fairly short.
Pretty much you could say that about most western societies more than 300 or 400 years ago and many much more recently.
Actually, early hunters had pretty good lives, not terribly hard, danger levels are debatable, and not short lives. As a zooarchaeologist, I studied paleodiets for over 25 years, working with physical anthropologist and paleobotanists.
By and large, hunter-gatherers were healthier, worked less, and had comparable or longer lives than their modern American colonists or western industrial revolution counterparts.
It is all rather relative. There lives may have been very different, but not necessarily worse or more dangerous. It sort of averages out when you think about it. You could die from being killed by a bear or auroch as a stone-aged hunter and gatherer or by industrial accidents, poison, and/or poor safety conditions of the industrial revolution. Either way, you were living into your mid 30s on average, assuming you survived the high infant mortality rates. The difference is that the stone-aged hunter and gatherer was probably working less than 30 hours a week at survival whereas factory workers often worked 12 hours a day or more, 6 or 7 days per week during the IR. Never mind the dangers of the 1700s and 1800s fishing industry folks.
When it came to hunting large game, prehistorically, as far as we know, in most areas it is not the major source of regular food, but the occasional source. Part or how people minimize risk is by not hunting game that will kill them as readily. There is a reason why, for example, there are often plenty of deer, rabbits, rodents, etc. in the middens of prehistoric Native Plains villages. Also, smaller game may be more readily available on a daily basis than large game. Studies of historic, technologically primitive groups have shown that the procurement of big game also often corresponds with particular types of ceremony and rights of passage.
I had a chance to spend time with Richard Gould back in the 90s. He spent a lot of time with Australian Aborigines. One of the stories he recounted was a hoot. As a very sexually stratified society, the men hunted and the women and younger children gathered. The men "hunted" many days, but often came back empty-handed. The women gathered plants and killed lizards, snakes, insects, and small game as encountered. Gould noted how most of the game was being procured by women and so he went hunting with the men...who often went as far as the first shady place out of sight of the women and spent the day in the shade, chatting, smoking, and resting. Then the men returned home at the end of the day, noting they had seen nothing. We the women reported seeing game, the men would then sometimes go after it. So from a risk perspective, the men reduced their risk of dealing with larger game by engaging in infrequent actual hunts and letting the women do much of their scouting for them.
In many aboriginal societies around the world, learning to be a hunter by boys meant procuring small game on a regular basis. It is the small game brought in by young boys that often was what was cooked at the end of the evening on a daily basis.
New World Clovis hunters didn't just go after mammoth and other megafauna all the time. People, even prehisoric people, were not dummies. They utilized what they could when they could (with the possible exception of food taboos). Megafauna was game sometimes utilized when it was thought possible, practical, necessarily, or out of ceremonial or traditional reasons.