Its not really about comprehensibility. The characters, especially to a white American audience that is accustomed to being catered to, become less relatable if they have an accent. It almost certainly would have had an impact on commercial success, especially in the 90s or earlier. The relatability of secondary characters is less important.

I know white kids that legitimately thought Aladdin was white. As a PoC it was fascinating to hear to say the least. It was a deliberate choice to make him fairer than Jasmine and to ensure he had no facial hair (which was the aesthetic preference of white Americans at the time).