That will never happen. Nobody will make real software for iOS because nobody wants to pay a 30% fee for the privilege of randomly having their whole business shut down when an app reviewer is in a bad mood.
Are you referring to IDEs? The iPad is not a productive machine. It’s for consumption. The VisionOS is for productivity which is very different from anything on iOS so I imagine it’s going to be available on it.
I don't see why you couldn't port an IDE to ipad os.. filesystem is a bit tricky with the way icloud files work.. but otherwise it's just a thing.
I think mostly people don't (for high end IDEs) because they expect a keyboard and pointing device that isn't a touchscreen and those are faily rare per ipads sold.
The ipad pro certainly is seeing some more beefy productivity apps it seems.