Nook Ereader problems

We've just had to transfer to Sainsburys from Nook for our Nook E-reader.  Why can you only transfer bookd through Digital Editions using a USB cable?  I've never had to use a USB cable to carry out ebook transfers and have always done them over wifi - this is a huge step backwards. Device has always been over wifi and no usb cable was supplied because of this.  Can anyone help before I chuck this in the bin and buy a kindle instead??? The adobe Digitial Editions software is old, antiquated and not user friendly