Why do most belly pork recipes recommend cooking the pork at a high temperature at the beginning of cooking?

Most belly pork recipes recommend cooking the meat at a high temperature at the beginning. And then lowering it for a number of hours.

However, I have found that when I do that, the skin rarely forms decent crackling. Presumably because the skin is still a bit wet and it takes time for it to get hot enough to crackle.

I have only had success when I turn the heat up at the end of cooking.

Why do all these recipes recommend the opposite of what is working for me?