Well, two of the older boys have their own businesses to run. There is upkeep for the house and property, upkeep of their equipment, and the rental properties (which can take up a *lot* of time and effort, I know my dh will be grateful when our boys hit their teens and can work alongside him. It'll be good for them, helpful to him) Most of their boys are at the younger end, and just like the younger girls, they don't have the bulk of the chores. In their buddy-lists, there are 3-4 kids each, with one older one, and the little boys are included and help with whatever "jurisdiction" is assigned to that group.
We don't actually see the older girls "working all the time" as some claim.
When they are
doing chores, it's mostly household stuff and thus visible to viewers, but IMO that gets conflated into "Oh those poor girls, and look at how the boys do nothing." They definitely have gender-differentiated roles, but I don't believe that means the boys are getting off with doing nothing for the family. We believe much the same as the Duggar's in that area, but believe me, my boys know how to make a bed, sweep a floor, and wash the dishes. One has an interest in cooking and we encourage that.
Although our major focus for them will ultimately be getting them to the point of being able to provide well for a family, that doesn't mean that everything else is ignored. If they're single for a time, they need to know how to take care of themselves.
They have also switched out the chores (boys inside with mom, girls helping daddy), and say they do want all their children to at bare minimum be proficient in every area. I tend to take them at face value, so I believe them, even though TLC is not showing much of their normal daily life anymore.