Latter-day Saints read Isaiah’s exclusivity statements as being about idols, not about whether exalted beings exist elsewhere. Psalm 82 says “you are gods,” and Jesus quotes it in John 10. Isn’t the Bible’s own language on the LDS side?

The polemical context is real: Isaiah’s primary target is idolatry. The statements go beyond idols are false, though. I am God and there is none like me (46:9) is a claim about uniqueness of kind, and it is the claim first-century Jews, including Jesus, understood as strict monotheism. Psalm 82’s gods are, in the psalm itself, condemned to die like men, which is not a description of exalted beings, and Jesus’s use of it in John 10 is an argument from the lesser to the greater about the word’s application. Read Isaiah 43:10 and Psalm 82 in full, side by side, and compare.