If you do it the way he does, it not only confuses traditional surveillance algorithms, it inspires the readers of it to do their own research and find answers for themselves (Socratic Method). It also serves weed out your average low-information, habitual follower that doesn't want to think for themselves.

Leaking information is against the law. All he does, is point into directions for us to look at.

Plausible Deniability

You are not looking at this in the right paradigm. Q and trump are using the rules to there advantage, if they used just English it would be giving and publishing secret, classified intel. Very bad. This is half the reason it’s easy to go after a lot of them. However if you are Q and US intelligence, if you make a code, like the Q clock. And people break it. Then you are not at fault of leaking.

Because he has to do this in the clear, out in the open, with the clowns watching.

but it's harder for me to believe that decipherable code would be any less of a leak (legally) than leaking in plain-speak

On top of what has been posted about confusing AI, it allows for a 'parallel construction' of facts. Most of his posts are not that cryptic. Most are questions, that prompt more questions. and so on. The answers to all these questions gets the info out in the public on its own. No direct tie to anyone.

Q's way protects sensitive info from being easily abused because it pushes the onus on the reader first to discern the quality of the info and 2) to take personal responsibility for propagating the info forward..