I disagree. I used to think this way, but not anymore. You can get stuff done with the iPad.
1) When combined with a bluetooth keyboard it is really nice. The advantage an iPad has is that you can use it in landscape or portrait, with or without the keyboard, so you can read on it comfortably in one situation and create content in another. People don't read entire books on laptops because it is unpleasant to do so. The iPad is fun. Personally, I much prefer taking notes by hand and scanning them into PDF form later, but if you do want to type your notes in class, the iPad is perfectly fine.
2) The iPad has a longer battery, so it makes it through the day without needing a charge--classrooms often lack adequate power supply. I probably get 90 percent of my work done on the iPad. Here is more detail about how:
https://forums.macrumors.com/threads/1197650/
3) The iPad is much less expensive than any Apple laptop, and many Windows ones, and it gives students everything they need to get basic work done. If you are in a program that creates video content or other heavy processing, it is in appropriate, but that would be the exception rather than the rule.
@tjb1
As for the price of textbooks, they are outrageous, and in many cases ebooks are unavailable. I recommend buying them, scanning the content into PDF form, and then reselling it. Here is some advice about how to do this:
https://forums.macrumors.com/threads/1198956/
@ace198
Also, regarding the secondary market, thanks for that explanation. I wondered if that was the meaning, but it didn't make sense, because I didn't think there was reselling of k-12 textbooks anyhow. I guess he means university level then. Not much of a secondary market there either