It is realistic, but you have your work cut out for you, and you need to understand you can't fully ban them.
My son is 11, and finally got a phone, but with a talk and text plan, no data. He can take it to school but only if he thinks he is going to go to a friend's house after, so he can ask us/tell us what he is up to.
We fully understand he can just walk to the community centre to get WiFi, and recenlty told me how to access the School Board's WiFi LOL. In fact, he worked the AV club there managing all their gear for the school play. We fully understood he has the "knack" and we can't stop him, so we helped him, and by doing so, it built trust, and we explained why bringing the phone in the class is a distraction. It's not that the phone is bad, it just takes away from learning.
I have saying at home. When we eat, we eat. That means we do that one task, and nothing else. So in the class, when you learn, you learn.
They have their scheduled video time, weekends are 1hr morning, 30min afternoon, and 1 hour evening. If we take trips or go with friends, the time is gone. There is no "banking" your time.
The other interesting thing, and this was confirmed by my friend who is a high school teacher, is that Parents were the ones calling their kids the most during classes! Of course, there will be a boyfriend here and there, but overall, it's Grandma calling, or mom/dad.
Back on topic...we use an iPhone, because we can control which apps he can install, and it notifies us to approve/deny. This helps a lot. Also, Discord is a nightmare. Luckily, his account is installed on all of our phones, so we can see the chats, and some chats were REALLY bad. So we had a talk about them, and he even sided with us! SHOCKING!! I guess what I have to say is, if you are there with them in this journey, you are more likely to be able to guide them along, and be sure not to make a big deal if something bad happens, like a chat where someone posts inappropriate pictures, e.g. Porn, etc, and just direct them to the correct path.
Btw, my 11 year old can change my car tires and use all my power tools. He really has the knack. So that's why we knew banning wouldn't work. My younger son hasn't shown the same maturity, and generally follows along the rules that his big brother follows. So the effort you put in one kid, could be reused after. Although I don't think we will get our youngest a phone as early as our oldest, as he is happier playing active sports. He tends to be grumpy and doesn't handle losing at games, and doesn't know how to fix a controller that stops works. So his view of technology is not the same as our other son. So be aware that every kid is different in skill and cognitive abilities.