Maybe not surprisingly, the real money in this field is in maintenance and ensuring uptime. The robots are cool to develop too but its really hard to get a job doing that directly unless you're a startup with funding from a VC or have an incredibly good resume, but there is a cottage industry of people (businesses or business units usually) that make lots of money maintaining deployed fleets and developing patches / augmentations for existing robotics.

I think its hard to break into in some respects, compared to other fields (you need some certifications iirc in addition to a degree) but my limited, anecdotal exposure suggests its quite interesting and lucrative.

That said, my sample size is small, and on the other end of the spectrum, I know a few folks who maintain complex CNC equipment and develop software for it (using a language I don't recongize, I think its proprietary) and while they make good money, its not better than you can make as a senior engineer at a reputable place as a web developer, for example.