Lutris does the same. I don't know if it has Amazon integration but it has itch integration which is more relevant to me. It also used to have pretty good gog integration where you just log in with your gog account, pick a game, click install and play. It would even find all the DLCs you have for the game and offer easy installation of those as well.

But recently gog has started changing the names of their install executables so the installation scripts lutris autogenerates fail due to not finding the correct installer. It's not every game as some games still use the old naming convention but some games require manual installation and if those games have DLCs then those become an extra annoyance due to how gog handles the installation of DLC.

That's why I'm interested in Heroic because if it's still as convenient as Lutris used to be then I'm willing to sacrifice itch for better integration with gog because my gog library is much bigger than my itch library. But if it's having the same issues as Lutris I don't see a reason to pick Heroic over Lutris because Lutris has more relevant (to me) integrations and I'm pretty familiar with how to use it as a tool to get troublesome games running. I just don't the benefit of learning a different software if it's not going to give me any benefits over what I already use.