Recent reviews on Steam are reporting that online multiplayer initially installed EGS with the game for online multiplayer. This seems to have been expanded to require EGS to play the game at all, even if launched through Steam (https://steamcommunity.com/id/Tech-Gaming/recommended/1599660/). If someone can verify this the DRM section may need updating.
Topic on Talk:Sackboy: A Big Adventure
I know it requires Epic Online Services (EOS) for multiplayer and installs that by default, but can be uninstalled. I think you thus mean EOS instead of EGS (Epic Games Store)? EOS is not a DRM solution, but just a network infrastructure the game uses; bit like Valve's Steamworks. So, it indeed uses EOS, but not EGS to my knowledge, thus not requiring the DRM column of the Steam row to be appended with it.
Looking into it some more (mostly from Steam forums messages, since no official statement seems to have been made about it) EOS is installed with the game and used by default if an Epic account is linked. However at least one person has claimed that it uses Steamworks networking for online play if an Epic account isn't linked (https://steamcommunity.com/app/1599660/discussions/0/3464983493941801411/#c3765606580163535825). Maybe a mention of the mod linked in the post could be added for those who prefer to use the Steamworks networking?
I honestly highly doubt the devs of this game went to the trouble to implement two probably very different networking backends; would cost much work and would probably split the userbase. I'll look into it when I have the game installed again on my new PC, which will probably be somewhen next week.
Do you own the game yourself? If so, what does your own testing reveal about this?
I don't own the game myself - I was trying to use this page itself to see if EGS was required on the Steam version, after seeing the above-linked Steam review. I wanted to be sure you could use it without Epic, hence the interest.
Ah ok, already suspected that and is good. So far know of no games on Steam that require EGS to launch, only some games use EOS for online services thus.