It's good to hear that the coffee sacks get re-used. We have so much waste packaging around generally.
I've built my share of furniture. Son had a 'cabin' bed that made me swear a bit. That got passed on when he outgrew it. Power screwdrivers are wonderful things. You just need all the right bits.
There is always someone needing coffee sacks it seems, so we always manage to pass them on somewhere instead of them being thrown away. I think the instruction makers presume the person making it can not work out which things need a manual screwdriver - obviously the round clamps which grab a bolt you screwed into the other part and then pushed through so it just shows in the circular hole - need a manual screwdriver. I am not however screwing in manually 6cm long self tapping screws - aside from time it's good way to get a repetitive strain injury.
I've had blisters from using a screwdriver. I'm happy to avoid that.