Why does the songs sound down-pitched during live concerts?

This isn't the case with LTOW, ATTN, and Body Bag as they basically remained the same, so I don't get why 95% of their songs they peform live are down-pitched.

They sound ankward and they're not the type of pitches I grew up with, except Doubt Me and Sick of me, I think their pitches when performed live sound WAY better than the original ones.

Not sure if anyone have talked about this or is aware of this but maybe it felt like it needed some discussion.