NP completeness would still be of interest for particular algorithms because it would prove that those problems could not be solved in polynomial time. For inst

NP completeness would still be of interest for particular algorithms because it would prove that those problems could not be solved in polynomial time. For instance, if factoring was shown to be NP complete, that would be a really useful result both for showing the security of algorithms like RSA as well as potentially disproving the extended Church-Turing thesis if quantum computers can be created.