Apple should bribe a few people inside repressive governments
To have any zero click software their government acquires installed onto an Apple controlled phone "posing as" that of a journalist critical of their country's government. Apple can then dissect the malware, patch it, and the company selling it either rolls out a new zero click (lather rinse repeat) or they don't have another one and they get a bunch of very bad people repressive governments after them for having software that "goes bad" within a short time and they have to close up shop and go into hiding. Win win!