Some claim that that hunter-gatherers spent most of the time for leisure and only 15-20 hours a week for foraging/hunting [0].

[0] https://en.wikipedia.org/wiki/Original_affluent_society

Technology evolved roughly 10 000 years after agriculture, only after society was at the point that you had relatively leisurely people that didn't have to till and keep watch all day. I wouldn't say agriculture kickstarted technological evolution, except for allowing for towns and larger tribes to form in the first place.

Agriculture is only around 10,000 years old (give or take, at least one tribe on the planet hasn't invented it yet). This is like saying nothing invented in the meantime since now (written language, most of math) is "technology"?

It is actually a fun fact when you think about the recent popularity of the Paleo diet and the anti-gluten sentiment.

I'm not sure what I said has anything to do with agriculture. Could you explain why agriculture makes lone people safer? Humans are not going to be bear/lion/tiger food even alone if prepared properly. We are very dangerous/inefficient prey with just a sharp stick or two functional legs.

Agriculture encourages settlement, people can gather together for safety. Before that, they were moving around all the time, getting killed by a tiger was a realistic fear. Hunter gatherers had a tough life, even if successful on average.

If you've ever seen a brown bear...there isn't much you can do if you aren't armed with a gun, and even then....

Of course, the main benefit of agriculture was food security and surplus, allowing a whole bunch of activities not possible before.

Brown bears don't generally like human, as I have found repeatedly when seeing them in the wild. Your fear is ungrounded and irrational. Step one: don't interact with bear. Step two: don't smell like dead animal. Neither of these are hugely difficult and are easy to grasp lessons.

At no point was predation a major problem for humans. Again, nutrition and infection would most likely dominate hunter gatherer mortality.

How many remains have we found of mauled humans?

And yet a few people get killed by brown bears every year in glacier national park through no fault of their own.

Also as a PSA, playing dead works (better) for brown bears since they aren't so interested in dead things, never try that with a black bear who are more like scavengers. If you saw a bear in he states outside of northern Montana or Alaska (or yellow stone), it was just a black bear.