Steam became a home to PC gamers in part by absorbing all outside functionality. Why stuff your RAM with Fraps, GameSpy, TeamSpeak, GameFAQs, Metacritic, forums, or anything else? Leave your bags at home: it's all here. Stay a while.
By contrast, Epic's new store is a bare boutique. It's uncomplicated by old additions, nostalgia, and 'community.' I bought Hades there just now. The payment form is simple. The transaction processed immediately. The checkbox for developer emails is opt-in instead of opt-out now, so that's fixed. The download was quick and I was out the door.
The Epic Store is perfectly functional and easy-to-use, but given that Epic has made itself unavoidable, I want more from it (as I think most everyone does). Here's what I hope to see added to the Epic Store as soon as possible, what would be nice in the near future, and what I could take or leave:
Cloud saving: No modern game platform should be without the simple ability to store save files both locally and on a server. From what we've heard, this is coming soon.
News feeds: Epic Store games have FAQs, and may change their pages to reflect updates, but there isn't a simple reverse-chron feed of announcements. Instead, I'm sent elsewhere via social media links to hunt for the latest info. I don't mind getting dev updates in my email or on Twitter, but if I'm already on the platform I use to launch a game, I shouldn't have to leave to find out what's new.
Troubleshooting: Again, I don't want to have to join a Discord or find a developer's email address to ask a question about a bug or crash. If not built-in forums or something like them (which Epic director of publishing strategy Sergey Galyonkin suggests may be coming), I'd at least like to see a developer contact form, or a link to an offsite, troubleshooting-focused forum or subreddit.
Partying up: The friends list in Epic's launcher can only be used to chat with a friend who's online. If you want to form a party in Fortnite, for instance, you have to do it in-game. I've gotten used to accepting a party request through Steam chat and auto-launching Rocket League, and not replicating one of Steam's most convenient platform-game integrations feels silly. It's plainly useful.
Stuff that would be nice
User reviews: Ironically, some users are review bombing the Metro series on Steam to protest Epic, both hurting Steam and legitimizing Epic's concerns about user reviews. Epic is right to approach this with caution, but I do find value in seeing a snapshot of player opinions on a game. We're told user reviews will be opt-in by developers, whenever they arrive.
Account sharing: I've never used Steam's Family Sharing feature except to test it, but no one else in my household wants to play anything, so I'm not exactly the target audience for this. It certainly seems nice!
Version roll-backs: One nice thing about the Epic Store is that auto-updating can be turned off. I'd also like to be able to return to a previous version of a singleplayer game, though, which GOG Galaxy can do.
Mod hosting: While a lot of mods still have to be downloaded and installed manually, when Steam Workshop does have what I want it makes the process blissfully simple.
Store and library sorting: This isn't necessary right now, because there aren't enough games on the Epic Store to make it necessary. Eventually, though, the store and library sections will need to be more than grids of pretty images—and on the store, I'll at least want to see a list of new releases, or a few suggestions, though Epic has said that influencers are more important to it than in-store discovery.
Drive management: This is minor, but there's currently no way to move an existing install within the client.
TV streaming: Valve went so far as to produce hardware for this purpose, though the Steam Link is now being phased out in favor of smart TV apps. This isn't vital in year one of the Epic Store, but I use it often enough.
Take it or leave it
Screenshotting, livestreaming, and video recording: I use OBS for streaming, ShadowPlay or MSI Afterburner to take videos and screens, and I look to subreddits for other people's clips, not the Steam community. Many do use Steam for media sharing, but with so many other, better, ways to capture and share gameplay, I don't see these features as a vital part of a platform.
Profiles and groups: I've found some value in Steam's communities, but I prefer Discord these days, especially as the number of launchers I use has grown (not even including the Epic Store). I don't need yet another social network—just a useful friends list.
Gameification: I'm quite alright with leaving profile badges and account levels to Steam.
A marketplace: Valve loves its economies, but I'm cool with just playing a game without monitoring hat prices.