I recently trekked through a couple of prospectuses, stopping at each parenthetical to ask if it really needed to be there. The sample was neither large nor random but instructive nonetheless. I could say a good deal on both these subjects, but not today. All the other parentheticals were either exceptions or amplifications. Amplifications give additional information.
Exceptions qualify a more general statement in the sentence.
Obviously, these parentheticals were not inserted for any comic or other literary effect. But I don't think anything would be gained by replacing these parentheses with commas or dashes. Commas might only make things worse. The same can be said of dashes, which often travel in noisy pairs. Commas, in contrast, quietly occur at many places in a sentence, so you may miss the comma that signals the end of a disruption.