[Laakeri]

Well, it is also not proved to not be NP-hard, so it could also be NP-hard to our current knowledge. But you are right that researchers believe that it's not NP-hard.

[Ar-Curunir]

Good catch, you’re right, nobody has yet proven that factoring is NP-hard, but a ton of evidence indicates that it is highly unlikely to be NP-hard