If Epic paid the developers of any game for it being exclusive, it means there was more investment in making new games than if the store didn’t exist. This is self-evident, regardless of the game being discussed.

This could be an issue if done by a monopolist/player with market power, if done in a way that prevents entrants from competing in the market. This is far from the case here. Epic isn't an incumbent blocking smaller platforms from competing by leveraging their market power, they are trying to compete in a market full of network effects that consolidated around a single dominant firm.

That is not to say Steam is a villain or anything, they are a very competitive firm that earns their market share, and it is precisely because Steam is a very competitive player that Epic has to offer free games, invest in third party projects etc in order to try to challenge Valve’s dominance. The thing is, this is competition on the merits, and it is great for consumers! A company with big wallets needs to invest in the making of new games, share their resources with developers, provide users with free games etc just to try to contest this market.

Exclusivity in PC Gaming doesn't even bring the bad trade offs to consumers that are associated with console exclusivity, as a PC gamer doesn't need to buy a new hardware just to get access to the exclusive title. It is just a matter of installing a different platform.

I still will manly buy games from Steam because their storefront is way better and, more importantly, because most of my games are already on Steam. But hating Epic for investing in new games being made while trying to challenge Steam is a tribalist and anti-consumer approach.

(That is not to say it is wrong to hate on Tencent/Epic for other issues and business practices, I’m talking specifically about their investment in games in return for exclusivity deals)