As a current university student, I see a lot of iPads and Surface tablets in my classes. They have essentially replaced traditional laptops in any specialties that isn’t computer science adjacent.
You can handwrite notes straight your textbooks/slides or type with an external keyboard without having to carry around a textbook+notebook+laptop. It’s very convenient.
The only 2 reason I can think of is price and size. Even if someone needs to draw something that can’t be easily done with kbm, there are touchscreen laptops that can take care of that. But those do cost more than a cheap tablet and if you don’t need any other features that needs more power then tablet would be a cheaper alternative. I don’t get your second point of carrying textbook, notebook and a laptop tho, a laptop can already do all of that just like a tablet or even better. The only time someone asked me for tablet recommendations was when they needed something small to read on bed.
A touchscreen laptop is no where near the fidelity you get with the Apple pencil or a Samsung s-pen.
You just answered your own question about the notebook and textbook when you said someone wanted their tablet for an ereader. Tablets are easier to read on than a laptop, and you are able to scrawl in the margins. And in school we have it beaten into our heads that you learn better from writing things down than typing, so a lot of students have shifted to digital handwritten note taking.
I don’t think you have used a tablet for a while if you think they’re not as powerful as laptops nowadays. I specifically mentioned the Surface and iPads because the Surface pro is marketed by Microsoft as a equivalent to a laptop (and mine runs Linux really well). The iPad Pros run on the same M1/M2 chips as their Macbooks do, and honestly nothing comes closest to the pen and paper equivalent than the iPad+pencil (not even my Surface). I don’t see any other brands or Android tablets around, except for one guy in my human anatomy class that has a modded Nexus 7 and that thing is sick.
A lot of people don’t need more power than that in university or their work.
That was my first point mate, size. I don’t see the feature wise difference but I only tried the iPad pencil for a little bit and didn’t like it that much but could see people liking it.