Jehovah or Yahweh is an interpretation of what the names may have sounded like to the High Priest when passed on to the next one. Beyond that, nobody was allowed to know or pronounce the name, the actual pronouncement was never written and if it existed, likely had been lost to history around the first destruction of Jerusalem by the Babylonians.
The rest is just interpretation and conjecture over centuries, first by the Christian churches, later even considered by certain Jewish sects and Muslims. Phonetic writing over the centuries was minimal if at all existent, very few cultures (before the Renaissance, I think in the West, only the Greeks had a phonetic alphabet) were interested. And even so, even had the Tetragrammaton been transliterated in ancient Greek we have even lost accurate representations of that language, so we’re still making assumptions over a transliteration of an assumption of a transliteration of a proto-Hebrew word that had likely been lost centuries before it was ever written.
The name of God, a game of telephone lasting thousands of years across dozens of major cultures and hundreds of re-interpretations of this game. Must be real important stuff to God, someone should base a religion on it.