Folding phones.
I was so skeptical at first, and even now it seems most people still are. It's a complete game changer though. There's almost nothing I can't do on my phone anymore, due to the multitasking and the larger screen. I can comfortably use desktop websites when necessary for banking etc. I have watched many dozens of movies and tv shows on it. It's just nicer for reading and browsing the web, and makes your phone feel so much more powerful to have the tablet form factor. I've actually been travelling for over a month with no laptop, just my Fold and a Steam deck.
I'm also appreciating having what is essentially a 5G-connected tablet where in the past I've always dismissed the LTE-connected ipads as a gimmick. It's hard to justify paying extra for the device and then a monthly fee, but now that I have it I can definitely see the appeal of a tablet that just works anywhere you go. Except since it folds you can put it in your pocket too.