I'm going to preface the whole post by stating first and foremost that at YOUR wedding, you should do exactly what and only what you and your partner want to do. I'm going to offer some things to consider when deciding whether or not to have an unplugged ceremony, but the choice is ultimately yours based on your preferences. And that should be true of every decision you make for your wedding day.
Perks of an Unplugged Ceremony
Your guests are completely present and in the moment - this is (to me) the biggest perk. Your guests will take in the experience, will remember the moments, and the entire day/night will be more thoroughly enjoyed by everyone
No photos are photobombed by a cell phone being held up
You can control what photos/videos are shared with the world
The timing for when photos/videos are posted is also in your control
There won't be any errant ringer going off from someone who forgot to turn their phone on silent
There's a guarantee no unflattering photos/videos of you and your partner will be posted
You're hiring a professional photographer for a reason - you don't need your wedding day captured by just any person with a cell phone
Perks of Guests Taking Photos
You get a unique vantage point of your guests' experience of your day
Photos from guests show you what they found most special from the wedding day
You will (likely) have more guests than photographers, so if more photos is your preference, this is the way to go
Attendees have the opportunity to capture guest interactions more than your official photographer(s)
Asking guests to post photos/videos using a dedicated hashtag means you have even more memories from your day to collect
But once again, at the end of the day, your preferences should guide your decisions. Maybe you want an unplugged ceremony, but you want people to take tons of photos and videos at the reception while people are dancing and having fun. Or maybe you want the whole day captured through as many lenses as possible. Or maybe you want everyone to turn in their phone when they arrive and not get it back until they are leaving the celebration. Whatever you decide is best for you is what should be decided.