Hmmm... Not big enough (and / or fast enough) to “destroy Earth”, but, Bennu could certainly remove most of human civilization (and numbers).
From the images, it looks like Bennu is basically a big pile of rock and gravel, rounded by gravity into almost a sphere, but probably not very cohesive at all. That might make it rather easy to blast into small pieces, 99% NOT in an Earth intercept course afterward, when it is still months away. OTOH, in a close pass by situation, it looks like it would not take much of an impact or interaction with some small object to knock off a chunk, said chunk then possibly* headed to Earth, with not much warning time.
*The odds of that are quite low, but 1/10 of Bennu would still have the potential to make quite a bang if it impacted Earth...
Similarly, an attempt to “push” Bennu, such as with a near miss warhead, would have to be done carefully, to not break it apart in an undesired manner...
262 meters, yeah, that would be a pretty bad one if it were in one solid piece.
10 Things to Know About 101955 Bennu
https://solarsystem.nasa.gov/small-bodies/asteroids/101955-bennu/overview/
Bennu’s density is only about 30 percent more than water. This suggests the asteroid is probably a loose collection of rocks, like a pile of rubble... Bennu has a close approach to Earth every six years... has a 1-in-2,700 chance of impacting the Earth during one of its close approaches to the Earth in the late 22nd century... of all of the planets, Bennu is most likely to hit Venus