You can't. It is just a matter of reducing the risk surface. With a GET someone may add parameters, with a POST they would send the data in the post (which is often the main point of a POST).

Since all typical web servers/processors only loh the call and not the body there is a lesser probability of a leak.

I am writing this as someone who manages cybersecurity and is offering faced with not enough information in investigations because of that. This is also the reason that I used "typical" and "usually" above - it is pretty weird what people send and how they process what they receive.