Out of all the names of God, why is “יהוה” so holy?

Non-Jew here, simple question: Why out of all the names of God throughout all of the Torah, why is “YHWH” the most special?

Other names like Shaddai could be pronounced in prayer/recitation, but ‎”YHWH” couldn’t even be said there. Only by the High Priest, only in the Holy of Holies, only on Yom Kippur. Why?? It could’ve been Elohim or Ehyeh, but ‎”YHWH” specifically was too holy?