Scenics and Stage Management share many a relation in terms of type of skills needed for role, as well as simplified responsibilities. Both sectors are highly significant in all forms of industry and are very collaborative teams that require quick thinking, time management, and tight deadlines. Furthermore, both departments include at least one employment role which requires management of some form of creative team; For stage managers this is the entire team, whereas, for designers this tends to just be construction team.
These roles don't require you to only work within your team, as most of the process requires communication with other departments in order to access and pass on information about; ideas for the director, materials, budget, deadlines, etc, in order to be successful as a production/project.
In terms of future stability, both stage management and scenics have their flaws and compliments. For example I believe that its reasonable to predict that most careers, including creative arts, will be forced into hybrid if not fully digital working conditions. This would mean that roles such as Scenic design, and stage management would be kept mostly online, using digital/remote methods to communicate with the rest of the crew/create designs. The main anomaly that I have thought of in this scenario is the roles of Scenic Carpentry, along with Scenic painters, as unless the are remotely controlling machines to do the work, the would have to physically be with the set in a workshop constructing and decorating the piece ready for the production - this seems like one of the only roles that will stay in-person. In terms of how this would affect success rates within industry, I feel this mix of job types, and availability could create new opportunities for many as it would create more availability and flexibility around the careers people want to go to.
Overall, both sectors are very intertwined and require very similar skills making one a great fall back if the main career plan falls through, this is also aided by the knowledge both sectors are still in high demand after the recent pandemic. Furthermore it is made very apparent that on any moderate scale production these areas of industry would not be able to function properly without some reliance on the other.