That's cause when Christianity spread out from the Middle East a lot of its' original flavor got diluted by the predominantly Hellenistic worldview of the Mediterranean, and so most art depicting abrahamic angels took influence from art depicting minor hellenistic divinities that had similar roles as angels. The Japanese lack that Hellenistic filter when they look at the original text, so when they see something un-greek but cool they run with it.

Now to be completely fair almost every biblical angel not part of a symbolism heavy vision looks completely human if you ignore their divine nature. But if you're in one of those symbolic visions a lot of angels tend to have symbolic features slapped on them that make them sound incomprehensible when you try and describe them later.

Still amuses me how Japanese media like Bayonetta and SMT often have more Biblically accurate depictions of angels than media from countries where Abrahamic religions like Christianityare more common.