The short answer
Yes, if solitude matters more to you than ease. Erg Chigaga, beyond M'Hamid el Ghizlane, is a large, remote dune field with few camps and very dark skies. The catch is the journey: the tarmac ends at M'Hamid, and the last stretch is a 4x4 piste across open desert. Plan two nights.
In more detail
M'Hamid is the last town on the road south through the Draa valley, about 98 km beyond Zagora. From there no paved road continues. A high-clearance 4x4 with a driver who knows the piste takes you out across the hammada to the dunes, a crossing of an hour and a half to two hours depending on conditions. Your camp normally arranges it.
The reward is space. Chigaga sees a fraction of Erg Chebbi's visitors, there is no road along the edge of the sand, and at some camps the nearest neighbour is out of sight. Its dunes are lower than Erg Chebbi's highest crests, but the field is large and feels empty. Mobile signal stops at M'Hamid.
It is the better choice for a second Sahara trip, for photographers after a dark sky, and for anyone who finds the idea of many camps along a dune edge off-putting. For a first trip, or with young children, Merzouga is simpler. M'Hamid holds a nomad festival each March, if you want a reason to time a spring visit.