> but I don't see why a (pre-historic) humans have to work that much harder than a tiger merely to eat and reproduce and live long enough that enough survive to do that.
This is a baffling comparison.
A tiger can sleep outside wherever it wants. It has fur to stay warm. Its offspring are up and running quickly on their own. A tiger can chase down animals and eat them immediately, raw. A tiger can drink water from a stream without getting infections.
The list goes on and on and on. If you think it’s trivial to live off the land and find your own food and shelter, why do you suppose people aren’t doing it?
Have you ever seen videos or documentaries about people who live in the middle of nowhere in self sufficient manners? They’re not having a great time. It’s hard work. Their health declines and they suffer. Their clothes are tattered. They still use a lot of cast-offs and tools and other things that they can find or acquire from society.
There are a ton of studies showing many tribal subsistence societies worked a little less than a tiger[]. Here's one, but they've been trotted out lots of times.
As for meat, yeah I've eaten lots of raw meat and seafood. Even better if you immediately caught it. Not a lot more work though if one tribal member makes a fire, catching it is more intensive than throwing some meat on some hot rocks to char the outside. There are also a lot of places/climates on the earth where you can survive without a shelter that costs more than a very small fraction of your total time to maintain and build, this is where many of the tribes ended up.
Regarding the young, cubs stay with their mothers for 2-3 years or about 20% the life of a tiger. Tribal kids stayed glued as strongly dependent on their parents until they were closer to 12, so a little bit longer than 20% of the lifespan of someone who has already survived long enough to mother/father a child (life expectancy was low in tribal times, but much larger expected lifespan by the time you reach the age of reproduction). A win for the tiger, but not by a longshot.
>A tiger can drink water from a stream without getting infections.
Nah the tiger can also get infections.
I think you're conflating the fact you wouldn't find it fun, with the idea that they were working that much harder than industrial societies. Industrial societies get more for their work, but due to the economies it actually might cost you even more time to get to a relatively self supporting subsistence level in some industrial societies since you would get arrested for being homeless, get arrested or kicked out for building a hut on your own land (you must spend a gazillion dollars on an up to code and permitted house), you'd get arrested for most forms of hunting, you'd have to pay to pick most wild growing fruits, etc etc.
Overall the tiger provides a pretty useful comparison of time spent working, although the tiger (or night monkey, again if you prefer a closer animal) does appear to have worked slightly more depending on which study you go by.
[] https://www.pnas.org/doi/10.1073/pnas.1906196116