Folding shovels are convenient to stash away, but unreliable in my experience, especially if you are out at the ends of the earth and digging anything larger than a sapling. I used to bring one, but not anymore.
You need something you can jump on, twist, smash, hammer, and is guaranteed not to fail.
A stout, solid root shovel is a safer bet. You can get more leverage too. And even if you dont need a big shovel, there are stubby shovels that can fit into a backpack that are way more solid than folding shovels.