Magnet links are more secure and remove the need to hash individual files in order to protect them against cyber threats. The .torrent file contains tracker URL, names of files to be downloaded, and hash code.
Magnet link will essentially remove the middleman and connect you directly with the source using the hash code. Your torrent client will use this hash code to find peers who are uploading the required files. There is no need to download the torrent file or even the tracker. This saves bandwidth of the hosting site as well as the users. A win-win situation.
While most torrent sites offer both the options, downloadable torrent file and a magnet link, Piratebay recently announced that they will discontinue hosting torrent files altogether. This, in my opinion, signifies a change that will gradually be adopted by the rest of the internet and for good reason. 153554b96e