If someone drops a nuclear bomb on a city, it causes vast, sweeping changes to that city very rapidly. If someone intentionally builds a machine that is explicitly designed to have the power and motivation to remake the world as we know it, and turns it on, then that is what it will do. So, it is a question of whether that tech is likely to be developed, not how likely it is in general for any old thing to change the world.
If someone drops a nuclear bomb on a city, it causes vast, sweeping changes to that city very rapidly. If someone intentionally builds a machine that is explicitly designed to have the power and motivation to remake the world as we know it, and turns it on, then that is what it will do. So, it is a question of whether that tech is likely to be developed, not how likely it is in general for any old thing to change the world.