Skipping flashing always feels like a “meh, it’s just a shed” move until the first sideways rain hits. I’ve seen folks get away with it on open-air storage or super basic lean-tos—stuff where you don’t care if it leaks. But the minute you want to keep anything dry (or insulated), skipping flashing is rolling the dice. I’ve tried to shortcut it before… ended up with soggy plywood and a weird smell that never left. Maybe if you live somewhere bone-dry? Otherwise, it’s just asking for trouble down the line.
I get where you’re coming from, but I’ve seen plenty of sheds last years without flashing—depends a lot on design and location. If you’ve got a decent roof overhang and you’re not stuffing it with valuables, sometimes it’s just not worth the extra time or cost. That said, if you’re putting in windows or planning to insulate, yeah, skipping it is just asking for rot. I guess it comes down to how much you’re willing to gamble with what’s inside.