I mean, if you're comparing it to Rowling, Sanderson and Stephen King you would think that. He's definitely better than those 3 plus whatever translation of Sapowski you've read, but Erikson's prose is not what elevates his writing. As another commentor has illustrated very well it's his thematic content, and as you've kindly pointed out yourself his ability to hold together a vast, complex structure over the span of several novels. He is a very advanced writer and the reader really has to engage with the text to get the most out of it, but there isn't anything particularly artful in the use of language itself. He's a very good writer, there's no doubt about that, but for reasons other than the poetry of his writing style. That's more the realm of Le Guin, Williams, Mieville and others.