Dry ice blasting will not remove paint from drywall, for instance, as that has become a part of the paper covering and is essentially inseparable. Really old block walls are also a problem as they are so porous that the paint has penetrated deep into the surface. Also problematic is many layers of paint. Recently we did a peeling paint removal job at a factory facility in preparation for a new manufacturing process. The paint in about 2500 square feet of ceiling was really peeling badly, and all that was required was to stop the peeling paint from falling, so it was an excellent candidate for blasting.
Budget affects the job as well, often dry ice as a media blast option can remove a substantial portion of the existing paint, but the time it takes is so long that the costs outweighs the benefits of removal.
Using dry ice blasting to blast all the loose and easily removed paint gets almost every wall ready for a quality top coat of paint, and it does this without the dust and messiness of traditional sandblasting.