I've used Steam chat and voice comms all of about 3 times. Discord is better.
Profile pages and achievements? Couldn't care less.
Streaming? There's Twitch for that.
What I really care about from a platform are the games that are available for it. Valve waved the white flag on that a while ago when they abandoned first party game development.
I don't need forums or screen shot galleries or any of that junk from my store. I just want games.
If I want to talk about a game or interact with other people who play the same game, I'll go on reddit.
Many people use any enjoy the features that steam provides. For example, I enjoy the ability to go to someone's profile and be able to instantly join their game. I enjoy the ability to organize events through events in steam groups. Many people I know use the Steam Workshop to share their fan-made content or the Marketplace to sell their items.
It's not just those features in the client though. Steam also has a number of integrations that developers can make in their games, such as achievements, integrating their multiplayer with steam (allowing for the aforementioned joining via profile), cloud saves, controller support, etc.
Right now Epic is missing many of these features and more. With that being said, what reason do I have to use Epic over Steam besides the fact that Epic has a few exclusives?
Stockholm syndrome?
Epic competed for developers on a more competitive split, but have done little to entice users; their platform didn't have even the barest of (edit:) feature* parity with Steam at launch (or even today), and rather than, say, fund new titles for their platform, they've largely paid for existing or in production titles to not appear on their competitor.
They're competing based on attacking their competitor (and/or users of their competitor's platform) rather than by bolstering the merits of their own platform.
It's a shallow distinction but a fair one for consumers to make. "We have helped create this thing for our users" is different than "We paid to prevent their users from having a thing."