The problem is that as I posted above unless these units have been fundamentally redesigned in the last 6 months since I last played with one, they're a total waste of money because they won't charge most devices at any more than 500mA. It doesn't matter that they claim 2.1A output - they don't have the smarts in them that a modern charger like an OEM or Anker has to actually charge a new Android or Apple device at full speed.
+1. The problem with built-into-the-wall chargers is that you're buying instant obsolescence, not just in terms of anything new that comes out but, because the circuitry is often several years behind the times, something from several years ago. The thing about Ankers and similar high-end chargers is that they're constantly updating them to deal with the latest charging nonstandard.
Look at Qualcomm QC 2.0 and 3.0, where you're negotiating fry-your-device currents and voltages (up to 12V and 3A, over a "USB" port), anything that has that charging tech built in, which means things with recent Snapdragon and similar chipsets, will need a QC charger to go with it. So you can either plug in a newer charging brick, or wait X years and then redo your wall sockets. When (if) the tech ever settles you can decide to build them into your house, but until that happens I'd go with a brick unless you want lowest-common-denominator 500mA charging.
Even then, plug in a dodgy USB C cable (and many/most are) and you'll fry the charger if it's a cheapie with little to no protection. I'd stick to a reputable-brand power brick.