I've always had a block of lard or shortening in the cupboard and have always used either a piece of the parchment paper from the wrappings or wax paper. I don't throw it out, keep it in the box for the next use. It becomes better with use, almost like a piece of cloth. I do throw it out only when I start to get more on my fingers than the pan. I don't think I would call that being wasteful.
I do have sprays but don't use them for baking. Did when sprays first came out but for some reason didn't care for it. Don't really think I can say why, just don't.
Mostly use sprays for roasting pans and their racks. Also for frying pans, quick coat then whatever type of oil the recipe calls for. Less sticking and easier clean up.
I only use butter for certain bakes such as Madelaines. Most of our butters, here come in foil wraps now. There are probably some still with paper but I haven't come across them. Because of the shape of the Madelaine pans I get a much faster, neater and better coverage to use my fingers.
I never thought of reusing that paper.