Tablets. I've owned 2 so far, plus fucked around with a third, fancier one that was borrowed from someone else (in case you care: a very old Samsung one, a Xiaomi model from the late 2010s, and a new-ish Apple iPad for the borrowed one).

They suck as smartphone replacements because they are too big.

They lack button inputs, so they suck as gaming devices or as computer replacements.

You can browse the web... But if you decide to type anything, the large size plus the touchscreen keyboard make for an awkward experience (in ways that it's not on a smaller phone)

They have lit screens, so they suck as eReaders.

They're sorta okay as like, personal screens for watching movies or whatever, but like, at that point just use a television??

They can make sorta good drawing tablets, the ones that are pen-compatible I mean... Because I mean, yeah. But the lack of a keyboard is a bummer with how I learned to draw with my other hand on Ctrl+Z, though that's more a muscle memory issue than anything.

In general, every tablet I used felt like a less-good verion of a dozen other devices, yanno?