I've had relationships where I just liked spending time with the person, even when just sitting and not talking, but I've also sat around on my phone not talking to people, and it's not at all the same. When you're on your phone, you're in your own little world trying to ignore everyone. When you're such close friends with someone that you even like sitting around and not talking, it's because you want to spend time with them so much that you want to just be around them even if there's no real "excuse" to hang out.