Yes - you can do all these things but when you create a social environment that practically requires you use technology, you're going to hand over the keys because there's no other option.

You can ride a horse to the grocery store. You might blame the Ford Motor Company if this is inconvenient, but Ford couldn't have made cars the default form of transportation if customers didn't buy them. And if Ford didn't make them, customer demand for motor vehicles would have been satisfied by someone else. Customer demand is the best explanation for corporate behavior.

I remember trying to delete Facebook because of "privacy concerns," guess how long that lasted?

It has lasted several years for me, and I have no plans to return. I miss getting some updates and invitations, but on balance it's not worth my time. I left my smartphone on the charger one Sunday as an experiment. I missed some messages, and nothing terrible happened. Have you tried asking classmates to contact you via other channels? Or creating a fake account just for classwork and leaving your personal details out of it?

When you say you "have to" use social media to communicate, aren't you really saying that it's simply more convenient than voice calls, personal visits, or written notes? You don't "have to," you choose to because it is the best of the available options (including the option of not communicating).

He's applying a rational-actor model to individual choices.

The rational-actor model isn't perfect; obviously people are not always rational. Can you suggest a better model for explaining or predicting human behavior?