Yes, there may be a “wide agreement” of scholars on that point, but that does not mean that any alternative theory is untenable. Obviously, Catholics prefer to subscribe to Petrine authorship. Nor are the reasons for rejecting Petrine authorship beyond criticism. For example, the introduction states among the principal reasons for supposing a late date of composition, “The author refers to the apostles and ‘our ancestors’ as belonging to a previous generation, now dead (2 Peter 3:2-4).” This is a fundamental misreading of the text!
to recall the words previously spoken by the holy prophets and the commandment of the Lord and savior through your apostles. Know this first of all, that in the last days scoffers will come (to) scoff, living according to their own desires and saying, “Where is the promise of his coming? From the time when our ancestors fell asleep, everything has remained as it was from the beginning of creation.” (2 Pt. 3:2-4, NAB)
It nowhere assigns the Apostles to a prior generation, and speaking of their “ancestors” in v. 4 suggests nothing about dating because it is referring to their all their ancestors “from the beginning of creation.” You would have to work hard to establish from this text any reason to assign this to a later generation of Christians. The only reason given in the introduction that has any basis in fact is that Peter seems to depend on Jude, but, even if so, this only weighs against Petrine authorship if we assume that Jude was written after the death of Peter, which is unnecessary. Don’t believe everything you read, folks.