For me it is. I've been using Lutris for years, but they're just stagnating. The design is all over the place, they still don't have a unified library, their native integrations break so often that I have to add my games manually anyways. And I cannot fathom why they don't adopt the same library integrations for GOG, Amazon and especially Epic as Heroic. They are much faster and have much less hassle.
At the same time Heroic has been adding the same tools I originally missed from Lutris. Like the Wine handling and using external wrappers like Mangohud or Gamemode or your own wrappers and variables.
Lutris' installation scripts are still often nice for figuring out a game's dependencies. I just wish they were in a git repo where people could add comments because some of the scripts are needlessly complicated.
If someone made an itch.io command line client that Heroic could tap into it would have most of the things I could wish for.