the problem with melon streams is that there seems to be no filtering system. seems like you can endlessly loop a song and each stream will count. you can tell because of the many songs with high streams that actually didn't chart that well but are from artists with massive fandoms. its even more suspicious because melon isnt reporting a lot of those streams to gaon which is supposed to include streams from all platforms. like there's a song with 400M+ melon streams that doesnt even have gaon platinum streaming certificate (100M streams). if melon themselves don't consider a lot of their streams legitimate i don't think we should.
mass streaming on youtube is a thing but youtube filters out low quality streams and puts a limit on the amount of streams an individual user can contribute per day. they definitely don't allow continuous looping of videos to count so fandoms can't completely manipulate this. dedicated fans help but you still need a high number of viewers to get a lot of youtube views