Epic purchases exclusivity whenever it can. Some games were kickstarted with the promise of being available on Steam until Epic gave them a sum of money to make them an Epic exclusive, screwing over their backers in the process. In some of those cases, Epic funded refunds to the backers, in others it didn't.

In plenty of cases this exclusivity also shut down cross platform support of the games. Fundraisers planned macOS and Linux versions of the games, but when Epic purchased exclusive rights they were effectively made Windows exclusives as well (Epic's store is only available on Windows).