This music video is currently the most-watched content on the platform.

most-watched 是由最高级副词 most（最）和过去分词 watched（观看）组成的复合形容词。watch 是动词"观看"，加-ed 变成过去分词表示被动含义。most-watched 字面意思是"被最多人观看的"，即"观看次数最多的"。