What's the science behind crashing after overclocking gpus?

Genuinely just a curiosity question, and I understand that it causes instability by pushing it past it's limits, and heat etc all the obvious stuff. But I just put a small overclock on my 4080super of 200mhz on the memory, and instantly get crashes on marvel rivals when just loading the game to the main screen, and when I revert to default I can game for hours without a crash.

I haven't overclocked in a while as I've found it not very beneficial to with newer cards, but I used nvidias built in overclock tester thingy, and got these issues straight after.

So what actually causes a GPU to crash with such a small change, when I wasn't actually in a game so wasn't that much stress, would it just be the initial power spike or something else?