A dependent spouse is employment-authorised incident to status and may work outside the business. Children may study and may not work, including in the family enterprise. Dependent status ends at twenty-one. And this category, for everyone in the household, offers no direct path to permanent residence however long it is held.
Renewable indefinitely, permanent never
The feature that distinguishes this route over a long horizon is that it can be renewed for as long as the enterprise qualifies while never maturing into anything else. Families who arrive intending a few years and then settle should confront that explicitly, because a decade of successful renewals leaves them exactly where they started in status terms. Children raised in that household reach twenty-one and lose dependent status, and their options at that point are their own: study, employment, or an independent route.
A spouse who has built a career on employment authorisation flowing from dependent status holds it only while the principal's classification holds. None of this is a reason to avoid the category, which suits many businesses very well. It is a reason to decide deliberately, and early, whether the family's actual intention is temporary or permanent, and to start any immigrant route years before it is needed.