90% of the people who use tablets I know (including myself) only has four use case: watching video, reading PDF and comics, taking notes, and playing mobile games.
All of which are very mobile-oriented tasks that are done on tablets solely for their screen sizes. With trifold bridging the gap between screen sizes and, more importantly, screen ratios, I would love to merge them into one device. This is in contrast with laptops, whose differences in OS and use cases are, to me, much bigger and necessary.
Of course, right now they are very much afar from consumers' pockets due to price and reliability. But normal foldables were once in the exact same state, and the fact that Apple is releasing one soon is a sure tale sign of the future of foldables.