It's pretty well accepted that the jets are powered by the Blandford-Znajek mechanism, and MHD simulations of accretion disks do show that the BZ mechanism can

It's pretty well accepted that the jets are powered by the Blandford-Znajek mechanism, and MHD simulations of accretion disks do show that the BZ mechanism can in fact generate jets. There are, of course, open questions about the details, in particular where the magnetic fields come from.