Not specially hard. And you're comparing different stuff. I'm not using a different phone because it's easier, but because having a smartphone is distracting. It's noticeable, but in case you need a link.
Incredible — the effect was present even when the phone was turned off. I would think that a phone that is off but nearby would be less of a distraction than a phone that is on but in the next room. It would take longer for me to turn on my phone than walk to the next room to get it.
https://www.sacurrent.com/the-daily/archives/2017/06/28/just...