You also have more clear space to work without a scissor lift there and not as limited to height. Look at all the other times a vehicle is on a lift where it's handy to have additional support for something. Like I said it's one more way of doing something. Is it for everyone? Nope. Is it worth the extra price? Probably to some people.
Suspension work. Lift the car, do your work, then load the suspension when you bolt it up.
If the arms can be synchronized, there are a fair amount of engine and subframe removals that it could be useful for.
I’ve done an engine swap in a ford e-series with a bus body. Used a lift to lift the body off, there was a bunch of stuff that had to be done under the frame, being able to lift it would make that easier.
A lot depends on the details, because it is going to get used as a normal lift a lot. But I bet there are a lot of six or eight bay shops where the extra arms would get used every day. That might be a reasonable purchase for them. If it generates a couple hours a week, what is the payback period?