SLAM and localization in general are early bottlenecks in mobile robotics solution, unless the core business of the product is localization itself (e.g. waymo, cruise, etc.) it's not uncommon for that to take a back seat during product development later on. In my experience lidar based solutions are more common out there due to their "simplicity" and safety for industrial applications (i.e. PL-rated)

You certainly can work with visual slam in the industry, but the job pool for that is not very big, I would say.

I work for a self driving doing mapping. There are definitely roles out there, more broadly look into other areas of state estimation.

It gets interesting when these systems need to be productionized and scaled. A strong software engineer who can speak the math is invaluable. My first year on the job was basically removing N^2 loops and making 3D visualizations.

Computer vision based SLAM definitely has use cases and you can definitely make money applying it at the right companies to the right set of problems. Building a whole career around a single technique, any technique, probably is probably not gonna work. You need to be broader than that.