How about Dota 2? There's nothing you can buy that can affect gameplay. Steam Workshop is used by community artists to submit their cosmetics, which gets voted into the game by the players. Steam Marketplace where players can buy, sell and trade their cosmetics. 25% of all Battle Pass[0] spending goes directly towards the prize pool of the yearly The International[1] esports tournament, with this year's tournament boasting a $34,330,068 USD prize pool, the largest to date[2].
[0]: https://www.dota2.com/international2019/battlepass/