Change doesn't always mean for the better... I think there is a desire to hate on steam and people point to fortnite as the creator of the epic store but steam has provided a reliable and secure platform for literally a decade plus while the epic store has had multiple breaches just this year alone and crashes quite often. The game itself is ok, it exists only because pubg couldn't fix their game though, that and the ability to play it across systems at any age, but to say it's a great game is kind of like saying McDonald's is a great resturant in that it's biggest appeal is that it's cheap, everywhere, and consistent...but that does not make it a great game in ant sense it just makes it a convenient game with market appeal and a payment system that works by getting thousands off of a hand full of people with expendable incomes or a serious problem.

Tl;DR he did alot of things but I don't really think he changed the game industry any more than league of legends or pubg.