There are several reasons why gamers might prefer the version of Batman: Arkham Knight :

The biggest draw of the GOG.com version is the lack of Digital Rights Management (DRM). Unlike the original Steam release, which initially relied on Denuvo, the GOG release is entirely DRM-free. This means:

The Ultimate Caped Crusader: Batman Arkham Knight (GOG v1.7) Batman: Arkham Knight