If you don’t understand the stats, what you shouldn’t be doing is arguing against them because of your personal experience.
Stats are the aggregate of everyone in the game. It doesn’t mean everyone has that exact win rate, though you could say the median and average experiences will follow the stats.
It’s just like saying, I don’t understand how only 2% of people have green eyes, when you and your sister and your mom all do, being 75% of your household, which is located in Ireland; where a lot of green eyed people live.
You need to understand there’s going to be outliers. There’s going to be some boar Priest players who queued up against a disproportionate number of Control Warrior/Paladin players. Others will get disproportionate opponents with garbage mulligans or a combination of both.