That was only on the '286, which required a processor reset to get back into real mode and was assisted by the keyboard controller, one of the Great PC Hacks. It is not as traumatic with '386 and beyond.
I also wanted to add that all this nonsense was necessary because int he design of the 80286 there was a method of ENTERing protected mode, but no clean way to get back. I'm curious to know whether the double/triple fault was used as a way back because that's how Intel had *designed* it, or if the lack of method to come back to Real mode was an oversight.
Looking at pages like x86.org, I tend to think the latter.
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