ETA After your SWH. How do your kids use the computer? Does it have access to the Internet? Are your kids allowed to explore and try different ways to use the computer? Because of the things you said in the beginning, I thought you are limiting exposure to tech stuff because you want them to know the real world. The real world is tech.
I see that you've changed your post to only be about phones. That is helpful. I would've answered differently if your initial post only asked about phones. In my view, phones use technology. How much you allow for using technology on their phones is your decision and unrelated to the big picture of how we use technology overall.
I hope that you do allow your kids to become tech savy and they
can explore what's available on the Internet. In today's world just having a computer is not enough. We need to be knowledgeable about what is available and how to use it, starting at a young age. You're not comfortable with technology. Your kids need to be comfortable using it. That is the real world. Deciding how much technology is allowed on a cell phone is related more to how responsible your children are than to technology.
I'm glad you asked the question about phones. Sounds like you now have a better idea about how phones fit into teens lives.
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I want to comment about keeping your children away from tech stuff. Tech stuff is the real world! Electronic skill is needed for nearly every job that pays much more than minimum wage. Pencil and paper as an important way of communicating is going away. Careers in medicine, law, law enforcement, education, offices, and more are run by computer. I haven't seen my doctors take written notes for a couple of years.I had the plumbing in my bath tub replaced. They used a tablet almost exclusively. The only paper was the contract. Casual photos are taken with a phone. The library is computerized. The catalog is on line. I use a computer to check out books. More and more uses for the computer.
I'm notified when bills are paid electronically. I can make deposits with my phone. My teen grandaughter has to do most of her school work on a computer. She does assignments and then sends them to her teacher by computer. My phone is able to do more for me than the desktop. My son in law takes notes in his college classes using an iPad. Tech stuff is a whole new large field. Those able to program, trouble shoot, install systems make good money.
I suggest that in my grandchildren's lifetime, they will do nearly everything using electronics.
Kids have to start getting used to computers, including electronics, while in the lower grades so they can hold their own in the workplace. They need to learn how to quickly use computers in college.