Scheduling, and homework assignments, and textbooks [0], and handing in homework, and communicating absences, and asking the teacher a question later in the day in a groupchat, and the teacher sending an extra thing for everyone to read outside of class even just out of general interest, and communicating with peers about something in another class groupchat where the teacher isn't present, and...
Some kids have zero interaction with pen and paper for at least some homeworks, where they'll receive the assignment in a class group, do it on the tablet, send it back there as a PDF, and get back an annotated PDF with the corrections.
Not all schools are doing all of that. Some schools are though, and most seem to have implemented some subset.
While doing this, the kids are not necessarily taught the basics of what's going on on their devices. They tend to not know the difference between, say: a browser and a search engine; a window and a tab; a menu and a tool bar; an operating system and a desktop environment [1].
Source: students of mine, telling me about their schools and how things work.
[0] if there is a textbook. It could just be PDFs of lessons, which could be all from one source or various sources.
[1] until I keep pestering them until they start to see a bit clearer, even though we're not doing computer subjects :)