The magnetism isn't what will move continents, well not exactly. It is true that while geologists have come to accept plate tectonics, the the mechanisms involved are not entirely clear. I was in school when one idea was that the ocean plates, being slightly elevated from the heat and activity at the mid-ocean ridges, own weight was enough a mechanism for the ocean to slide under the continents. It's not. That line of thinking is in line with the "uniformitarianism" view of the world. The catastrophism view looks for sudden and massive changes that show what once was stable was actually metastable and tripped into instability. Massive electrical discharges, heating up everything but in this case specifically long plate boundaries and fault zones, is thought to somehow lubricate the mantle/crust boundary, and the plates decoupled from the mantle move: like bumper cars as the core of the earth flips to align with the external electrical forces being applied to the earth by the sun and the galaxy, or like faces on a rubix cube moving all at once but the far less viscous oceans sliding up the invading continents and then sloshing back until the energy dissipates. I do not understand either of these versions better than the uniformitarian explanations of plate tectonics.

Geology is not super helpful because the time scales involved in what can be said about the past, and just lack of our ability to observe across those times scales or back in time, make it all more about 'is the story coherent' than what we can say we know for sure. Many rock formations look like they were deposited slowly over long periods of time, with fossils accumulating gradually. Other formations look like they formed very quickly and things look chaotic. There are mass graves of mammoths or mastodons where they are all huddled together fleeing some catastrophe. There are carcasses of them with undigested flowers in their mouths and even their stomachs meaning they froze and died instantly-- so fast their stomach acids did not break down the food.