Relying on hunting and gathering was also risky: A harsh winter would decimate your prey, and then you would starve.
I guess it's hard to have numbers, but early attempts at agricultural states (often in these same locations) seem much more fragile. Most collapsed within a few generations, to disease of humans or crops, or to weather, we can't know.
Neither did early agriculturists.
> early attempts at agricultural states (often in these same locations) seem much more fragile
That's because there are no hunter-gatherer states. Hunter-gatherer cultures are much too fragile to support the societal structures needed for even primitive states.
And to make sure it worked to your benefit (as the king) it was important that they farmed a limited number of things which were easy to keep track of, and easy to transport, and hence easy to tax. Like wheat or barley or rice, which you can inspect any time, and which ripens on a predictable date, on which your soldiers can show up to collect the rent. (And unlike potatoes.)
https://slatestarcodex.com/2019/10/14/book-review-against-th...
The comments there are generally of high quality, and you'll find some good counterpoints to the book's claims.
Counterpoint: "someplace better" might already be occupied by other humans. Besides, a harsh winter is not a local phenomenon, it affects entire regions. Good luck getting to "someplace better" if you're starving, don't have any transportation besides your feet, and don't even know where "someplace better" even is.
And of course without agriculture it's very hard to form a lasting society. People move around too much. Without society it's very hard to keep clever inventions from dying with their creator.