My personal headcannon for "a wizard did it"-esque cop out explanations for objectmons that look a little too objecty is "it came from the dream world." Pokemon looks like a literal garbage bag come to life? Some kid(s) had a nightmare after their parents told them their trash would come to life if they didn't take it out, and then those Pokemon escaped from the dreamworld. Pokemon has literal horseshoe magnets for "arms?" Awesome sci-fi dreams -> escaped from dreamworld. A Pokemon that inexplicably looks like the Roman alphabet and some punctuation? DREAMWORLD. etc.
Sure, you could try to come up with explanations like "well maybe the idea for horseshoe magnets was inspired by magnemite in the Pokemon world," but let's just save ourselves the headache of trying to consistently rewrite Pokemon world history so that object-mons inspired the objects and just lean into the object->objectmon causation and say they fell out of the dreamworld after someone ate a bad batch of slowpoke tail curry.
More of less this, you can say all object based Pokemon are based on a group of Japanese Kami (spirit), the
Tsukumogami. Bit of a complicated history behind the term (was just originally used to refer to raccoons and foxes which lived long enough to gain a Kami and become the Yokai (mythical creatures) tanuki and kitsune, respectively), it later became more associated with the idea objects that have existed for a long time (usually said to be 100 years) will become animate. There seems to be some argument whether the objects are just possessed by Kami or they become Yokai, but that's not an issue to discuss here. It's also said it's not just the object existed for 100 years that gets it a spirit but rather it can possibly change into a Tsukumogami but needs another triggering factor like some strong emotion linked to it. Infact, its specifically said throwing out a one hundred year old object would be enough to enrage it and turn it into a Tsukumogami.
Now there's a list of "official" Tsukumogari, many of which have become Pokemon. However being many of this information came from old Japanese tales and poems and how broad the general concept is, those are just examples of not only objects coming to life but in what way and what form they take. In addition to coming to life the Tsukumogari doesn't just stay what it is but not can move around, it does physically change. For example, the most famous Tsukumogari, the
Kasa-obake (an umbrella) has its handle change into a leg and grows at least one eye on the canopy which remains closed for the most part now (though, obviously through many retellings what it changes/gains also changed: two eyes, a mouth with a long tongue, arms, even sometimes gets a set of two legs).
At any rate, since obviously any of the explanation Pokemon gives for these objects coming to life hasn't actually happened in the real world (cause I find most icicles exposed to sunlight just melt) there does seem to be a magical element to the transformation as, not only it is alive, it can reproduce or at least has some kind of "genetic" material to pass onto a Ditto for it to lay an egg of it. If all else fails, just say one day Arceus looked down at at earth, saw an abandoned trash bag, and went "I'm going to bring that trash bag to life and make it one of my children".
(thoughts on every objectmon)
Just a few quick comments:
Magnezone: Something you'll actually see a lot in the Gen IV cross evolutions, they tried to mix things up. Magnezone is no longer just a batch of metal balls and magnets, it's now a UFO.
Voltorb family: Well they're mimics and in the first few gens did just that. Don't know how else they could lean into the "living Poke Ball" gimmick aside being able to have the colors and patterns of other Poke Balls (which would be awesome for them to do, like have it copy the Poke Ball it's caught in; could also do that with the Foongus family).
Unown: Are they objects? I always considered them conceptual. Eitherway, yeah, if any Pokemon needs a capability overhaul its the Unown.
Chimecho: According to the dex, the cloth is just a cloth as its the voice which reverberates. So it's not actually a chime but just chime-like.
Drifloon family: Turning into a blimp is its Mega Evo/Gigantamax. I think they're Ghost-type because they're based on how spirits are often drawn as balloon-shaped wisps, this is just a literal interpretation.
Trubbish family: Yeah, an issue I always had with them is that they kind of don't look like a pile of garbage, they look like a pile of s***. Trubbish is mostly alright, I'd say replace its arms with pipes that Garbodor has. As for Garbodor, honestly I would have made it evolve into a creature living inside a garbage can/dumpster (if they wanted to keep it poison just say the garbage can/dumpster is made of hard plastic; though would be neat if it became Poison/Steel, like have it evolve by trading it while holding the Metal Coat).
Klefki: I think the pink blob is the main body(?). As for why its there design wise, guess they felt Klefki without it felt empty. Could represent a charm/keychain too (though if that's the case maybe we could have the option of changing its color and shape).
Sandygast line: Don't get why Water Compaction and Rolycoly's Steam Engine doesn't at least reduce Water-type damage to half. At least make it take neutral damage if not resistant/immune.
Boy,
I've seen so many strange animals that would make for interesting Pokemon I don't know which ones I would ask for anymore if I was given the choice, lol.