Imagine being an enemy Pokemon that gets hit by an itemizer orb. One instant, you were a living organism, the next, you’re an object. This raises all kinds of existential questions that get scarier the more you think about it. At what point are you killed by the process? The best case scenario for you is that you die the instant the magic hits you and the rest is moot.
But if that doesn’t happen… Hoo boy. Will you feel your body being compressed and transmuted into an Oran Berry? Will you feel the excruciating pain as your nerves are destroyed at the atomic level to be turned into plant cells and sugar? The Lore in PMD very heavily implies the existence of some sort of life energy that animates living things, so what if that life energy stays in the thing you’re turned into? Object Pokemon like Chimecho and Trubbish exist, so it’s entirely possible that your life energy can just keep on existing inside the item you’re turned into. Imagine being stuck as an item, conscious, but unable to move and with no senses to tell you about the outside world. Nothing but your own thoughts to keep your company. You’re initially terrified of the prospect that you’ll be eaten if you turned into food or used up in battle if you’re an orb or something. But after days, weeks, months, without sensory input or anything but your own increasingly incoherent thoughts, mind broken by complete isolation, you begin to crave the sweet release of death. You begin to desperately hope that you’ll be gobbled up by the next explorer that happens by you, or deployed in a battle, or at least be taken to the recycle shop, anything that will let your aura escape and your life to end–at least you hope that’s what will happen when your “body” is destroyed. But it’s not like you can do anything to cause or avoid it, nor will you be able to see it coming anyhow. You just hope that you won’t be able to feel pain in this state, but in the Pokemon universe, not even that is a given.
I like to think it just swaps your location with that of an item.