Order of combining wet and dry ingredients when baking I've always learnt that you add the wet ingredients to the dry ones.

Looking at some recipes:

"Combine the dry ingredients, the flour ... Add the other wet ingredients, melted butter ..."

"Pour wet ingredients into dry and mix until just combined"

"Mix dry ingredients together, Mix wet ingredients together, and Combine wet and dry together and bake!"

"Make a well in the dry ingredients and then pour the wet ingredients into the well and mix"

Is there a reason to always add wet to dry and not the other way around?

Are there any types of recipes that , in fact, reverse the order?
The dry ingredients are lighter, less dense, and less viscous than the wet, which means they'll have a tendency to float on top of the wet. The dry ingredients that come in contact with the wet will form a sort-of skin, preventing the wet from distributing throughout the dry. You end up with clumps of dry, unmixed, and (ultimately) uncooked dry ingredients.

Pouring wet into dry forces agitation and more uniform distribution.