When doing tectonics, how necessary is a superconotinent?

[MrBragg]

I've seen a fair bit of advice on plate tectonics saying to start with a supercontinent and then break that up to get an idea of plate motions, continent shape / location, etc. Obviously earth has gone through such a phase a few times, but I was wondering, in an abstract geologic sense, is a having supercontinent a necessary / inevitable thing that has to happen on a planet where plate tectonics are operative, or is it simply a possibility rather than a necessity?

[Tiana]

If your planet is intended to be Earth-like, sure. That's a great way to start.

That said, nobody can see what ACTUALLY developed Earth, so, if you want to make a planet that was actually an asteroid filled with water by terraforming aliens and have it be earth-like in its contemporary-setting, or some other way of achieving continental chunks without a supercontinent breakup, or a planet that magically goes through rapid changes to its surface, causing no time for decay, or a planet that's made out of the bodies of an entire supercollective of sleeping fae folk, or whatever crazy idea you have that isn't "earth-like tectonics" then go for it! It happens to be the hobby of some to create earth-like settings and in that case they want earth-like ancient history to form that world so that when you look at the result, you feel a dissonance but also a familiarity.

I usually don't make supercontinents, I just eyeball the former connections and keep a mental simulation of how it's supposed to go. This is in part a choice I make because most people don't want me to worldbuild from the ground up but provide a sketch already.

If you want earth-like tectonics and plan to do a full world construction and have no fantasy/sci-fi means of world creation that negate the formation of a supercontinent breaking up over time, it would be a good place to begin. If I were to do it, I would make a huge continent in Other World Mapper and use the divide tool to break it up and manually calculate the drift based on my plate sketch and their directions of movement. I do usually do a plate sketch, or at least drop in the crucial plate borders so I know where earthquake heavy zones will be. That's something I think is worthwhile even if the full continental drift seems absurd to calculate. Do as much or as little as you feel passionate about! Worldbuilding can go SO deep if you let it, so pick the aspects of it that excite and interest you. Not everyone's going to make a conlang and not everyone's going to design continental drift.

[waldronate]

https://en.wikipedia.org/wiki/Supercontinent_cycle has some information on why you would start with a supercontinent and go from there. The general idea is that on a planet with plate tectonics, the plates will periodically get stuck together due to convective forces and then break apart again (it's pretty much unavoidable due to how the surface cools and subducts). If you look at the images on the Wikipedia page, you'll see that most of the very early continental crust has been destroyed or at least very highly altered.

Starting at the last supercontinent and going from there simplifies things greatly, because you're starting from a very few initial states. Things before that supercontinent are unlikely to have a huge impact on your final world state because a lot of that terrain is going to be planed relatively smooth by erosion. Looking at Earth, the last major supercontinent was around 300 million years ago. It pushed up the Appalachian mountains in North America, and they're relatively worn away at this point.

It a supercontinent inevitable? Probably, if tectonics run long enough.