Completely agree and I make a point of not getting my phone out on my commutes to and from work. Just letting your mind drift and relaxing is a good way to start and end the day.
If concentration is a power (super or otherwise) then like all power you only have a finite amount of it. Allowing your mind to just amble from one random thought to another is a good way of preserving some of that power for when it really matters.
There is also plenty of research about the damage that using tech does to your sleep patterns and quality of sleep so I try to stop using anything with a screen about an hour before bed. Lack of sleep = poor concentration = easily distracted by devices. It's a vicious circle.
And on that note goodnight!