It's also not like integer factorization or discrete logs have reached some kind of complexity lower bound; it's certainly not impossible that we'll get a L(1/4) method in the future as well.
Not impossible, no. But the fact that people have spent much longer looking for improved integer factorization attacks without making progress makes me more optimistic that integer factorization will continue to hold up to further scrutiny.
Not impossible, no. But the fact that people have spent much longer looking for improved integer factorization attacks without making progress makes me more optimistic that integer factorization will continue to hold up to further scrutiny.