Why is 90% of yoghurt "greek style" now

Because popular diets, especially linked with longevity and heart health, specifically recommend it. Real Greek yoghurt is just the full fat milk, creamy and filling. Greek style is not but will sell at a mid-price point. Might have additives in to change texture from cheaper natural yoghurt

On a slightly different topic, I work with someone who drinks sparkling water.... didn't know those people existed

I don't know but I hate it and someone should answer for this.

It is actually Bulgarian. I like only plain whole milk, “Greek” is just a label to sell it more expensive That’s why often, when I find a good one, I get a gallon of whole milk and make my own yogurt.