I have 2 uses for a tablet, and know 2 other uses. They're pretty niche.
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you can use it to get AT&T to sell you an unlimited 5g data sim for $20 a month and pop that into a hotspot if you need to work while being driven in a car or in more locations than there's necessarily easy or cheap wifi.
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Reading Manga / Comics. I do read some on my phone, but the ability to see the "full page" on a 6.7" phone aspect narrow screen vs a 10" wider aspect tablet screen is surprisingly large, and my eyes are getting worse, not better as I age. Teeny tiny is not the best experience.
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Using them as cheaper wacom tablets for drawing / artists.
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Work provided portable tools for all sorts of stuff that doesn't have any SIM or monthly fee needed / requested, and something that inherently isn't a phone.
Honestly, unless they come out unlocked for like sub $300 I'm unlikely to want to get one as I have had no problem using sub $300 new phones for 4 years now. And no interest in spending more for a tablet - I've gotten tablets for sub $250 for like 8 years now and they are good for my needs.