Hunter-gatherers and subsistence farmers have pretty similar workloads - by many estimates, subsistence farming requires more labor, even. The advantage in subsistence farming is consistency and food preservation, allowing for larger populations, surplus, and specialization.

If you make a stone spearhead twice a month, you might not spend much time thinking of how to do it better - but if you do it for the whole village, 60 times per month, you might be spending some of that knapping time thinking about how to make it easier.