Trekking Poles vs. Hiking Staff

Trekking poles. I can collapse them and store in my pack when I don't need them. Adjustable length makes it easy to use with tarps and some shelters. Nicer grips. I can buy replaceable parts for them. I can attach snow baskets, etc…
If I want a hiking staff I pick up one in the woods and leave it when I am done. Free of charge. I see no advantage to a hiking staff. Aesthetics aside.