Quite simply they are designed to be addictive. There are literally millions of different games available. Video game designers have to make their game popular. Popularity occurs when players return to play on a regular basis. Designers achieve this by making their game challenging enough that very few people get to the finish. They also ensuring that there are incentives or wins along the way. We call this intermittent reinforcement. It fires up the pleasure areas of our brains and is a great way to ensure a person wants to return. This is the same type of reinforcement that makes gambling so addictive.
Why should you consider switching to a dumbphone. You will have more time, be more efficient and more productive. I would recommend it because you will be less stressed, happier and more attentive to those around you.
Many private schools in NSW are now banning smartphones during school hours and all the feedback I have heard is extremely positive. Schools should be about learning and anything that hinders learning should be restricted.
There is now a phenomenon called 'Phantom Vibration Syndrome'. It occurs when someone regularly has their phone set to vibrate. They feel phantom vibrations on their leg - even when their phone is not present. Up to 90% of US University students experience these phantom vibrations.