I'm convinced there's hidden damage boost

Starting to become very blatant one team has a hidden damage boost to help them win which is why one team is always stomped. And it's more clear when they use ults that are not supposed to one shot even a support character that has full health yet everyone on that team is able to one and two shot people. What made it clear for me is that I was on a team that was being stomped, I had full health and a squirrel ult one shot me and there was no damage boosting characters at all. The other team were 2 tapping everyone, not even using combos. I've been ONE SHOT whilst using luna ult by someone like psylocke which shouldn't be possible and I had full HP, again my team was the one being stomped.

There is no other logical explanation as to why every single match except for VERY rare exceptions that one side is getting stomped. If it's too good to be true then it's probably not true. Disappointed and will be looking for another game.