I find it difficult to discuss this idea with you as you are unfamiliar with the Hebrew root at play here. You say that the word k-ph-r is the word for atonement, but that atonement is different from "removal" as if there is some alternate concept in the bible of "removal of sin" which isn't accomplished by "only" atoning.
Part of this might come from your idea of original sin which is a stain on humankind which cannot be removed. Jews simply don't see sin that way, so we don't see "atonement" as deficient in any way. You are starting with an idea that what is in the text doesn't match up to what is in your text. We reject your text and see the language in the original. K-ph-r is a root that means a variety of things including "to cover with pitch" because the noun for "pitch" is built on the same k-ph-r letters, though they are not of the same root.
Separate from that, the root relates to expiating and obliterating (as explained in Klein's Etymological Dictionary):
"Some scholars connect
כפר ᴵ with Akka.
kapāru, kuppuru (= to wipe off; to expiate), Aram.-Syr.
כְּפַר (= he washed away, wiped off). However, as shown by the Aram. verbs
כְּפַר and
כַּפֵּר, the meanings ‘to wash away, wipe off, cover, expiate’, are interrelated, and, accordingly, all the above words are etymologically connected. For sense development cp. Arab.
ghafara (= he covered, he forgave),
‘afa (= he covered, he wiped out, he forgave)."
So relying on "atone" as if that stands by itself as an incomplete removal is ignoring the actual meaning and use of the Hebrew word and attaching baggage to the English word that translators have chosen to use.