I have some very pretty, delicate dresses with invisible pockets stitched into A line skirts, where I can stash my car key, or a poo bag if I'm running out the door but first need to do a potty break for my dog. Or sometimes I put a tissue in there, or a little emergency pad. These are delicate pockets in the same lightweight cotton fabric as the dress lining, so they can't hold heavy things, like a phone, but they sure are lifesavers!
Most people don't know the full range of clothing that's out there. You would never guess that my oh-so-proper dresses have pockets.
And then I have sturdy corduroy or denim skirts with visible utilitarian pockets, sometimes in contrasting fabrics, where the pockets are an integral part of the design. Those I can put a phone in, or even a small wallet, and the vibe is more daily chores than summer wedding.