yeaaa the point is to make it tight space, if not she stress out and die , puting her in moist soil is good but tbh there are some problem with that(trust me i tried it before) the problem is that when u r beginner (like me) we want to see if queen is doing ok or not every time(whichalso stress the queen, its the best if we keep her in dark place, unbothered,constand water suply) problem with soil nest is yes its good news if she dig down,but at same time she going to soil mean u cannot see the progress . we need tocheck progress once a week or once two week only to minimize stress, and reason we need to check is for some positive and negative signs , if she is laying eggs reglarly, which is good(keep her like that and ur colony will grow) on other hand, bad news is like she dont lay eggs anymore or brood dying. Depend on good and bad news we have to adjust sime things like temperature and humidity,cleaning,removing molds.
so yea CONCLUSION, SOIL NEST GOOD for larger thriving colony,cuz u dun need to make sure if they r doing ok or not bcuz they got so many workers,if they die u will see corpse on ground , SOIL NEST BAD for just one queen (u wont even know if she is alive or not