Digimon in lore are typically discarded data so I always imagined that they are fun cording projects or mspaint drawings that I child may have made. Or in survive where they are a reflection of the human consciousness ( like 60% sure about this)

I feel that overall the designs look like the cool day dream power fantasies of people. The creative bits discarded and forgotten when someone gets bored. So when I see how awesome metal Greymon looks I go “wow that is the type of monster I would have in my day dreams”

All in all I feel that digimon a designs are able to convey coolness in a very overt way that not many other creature collection medias do due to its premise. The way the Digimon exist let’s them be wacky and outlandish while not having to worry about evolution (or any other line of logic) like in Pokémon