Most games on Epic Store are available on other stores too. How walled is this? And how much do they get for InApp-Income of the apps? Do they enforce it like A

Most games on Epic Store are available on other stores too. How walled is this? And how much do they get for InApp-Income of the apps? Do they enforce it like Apple and Google? Sometime (or often?) they have a time-exclusive offer for new games, but it seems they pay good money for this, so it's a simple business-descision for the gamedevs.