This might be the problem, what was recorded on the Iphone, should be listened on the Iphone. Also, when listening on YT, compression levels vary constantly, you never know what it is you are hearing. Which can explain the different reactions to the same video.***
Disclosure: I listened on headphones via computer. The sound there can be decent on actual professional recordings (not iPhone system recordings). So it's not that my playback completely sucks. It's the recording that sucks.