Hobbies that you want to discover more in, but no one in your immediate friend group knows. You want to go deep in programming, basketball, golf, whatever. There's multiple Youtube videos, subreddits, etc. for it.
Video calling? Chatting with a person from literally thousands of miles away? My grandpa used to literally write a letter on paper to his brother who was in the States. Now I can just call my parents with video calls.