A domino joiner on a job site would be good for things like putting together pieces or a banister (railing) where you needed both the strength or something like a doweled joint as well as the alignment capability of a biscuit joiner. It’s going to add strength to any kind of mitered joint that would be glued/where you don’t want to see nails. Most of the uses are going to be in cabinetry or furniture rather than in general carpentry and contracting, but it definitely has a few very specialized uses on a job site.

I am not a contractor, but I did it for a very brief period of time (until the business owner stiffed me of about a thousand in pay, and I realized it wasn’t a good side gig).