The Miami Dolphins didn't have a lot of options when it came to Jaelan Phillips. They could keep him and let him hit free agency, or trade him as they did to the Eagles. They could have also handed him an extension that may have further become a cap burden. Fans have been mixed.
Dolphins fans were not overly thrilled with the trade, but it made sense, and for the most part, those same fans knew it was a smart decision. The move made sense for the Eagles as well. Vic Fangio knows Phillips and what he can bring, so much so that he knew exactly what he was buying.