As much as I love some good overthinking, the Pokémon franchise so obviously follows what looks cool to the target audience that it's quite silly treating it as being in any way consistent.
You get car pokémons, teapots and other contraptions that just make 0 sense.
I dunno, I find the thought kinda hilarious that people might start well-actuallying Pokémon lore with "it's really metamorphosis, not evolution"...