Which part? Steam has tons of features and comes from a company that has been constantly supporting PC as their main platform ever since the storefront's release in 2003 or 2004 (apart from the Steam Deck, but that will also be kind of a PC-Linux port). I'm only not sure about their software integration, as I don't use it combined with any other software, but I imagine it to be flawless (based on other features that I use). Oh, and there's no platform exclusivity with Steam.
Specifically: rich kid swinging their pocketbook around (presenting Epic as if it's meaningfully richer than Valve is just silly - they're both mega-rich corporations); the CEO ego part (yes, Newell is far less visible and loud, but he wholly embraces the way the gaming community deifies him - different personality types, similar levels of ego); the exclusivity argument isn't a direct mirroring, but Steam's de facto monopoly and the inherent threat of losing money if you don't put your game on Steam makes this more than a match for any exclusivity payments Epic has made.
I also haven't seen any indication of Epic being opposed to PC gaming (or flip-flopping) at least since they opened the EGS. Now, two and a half years isn't a lot to go off of, but that argument goes both ways.
I frankly have no idea what software integrates with Steam - in my experience Valve wants their own solutions or none at all. No doubt there is all kinds of stuff I don't know of though. The only integration with EGS that I've come across is GOG Galaxy (which Steam notably lacks official integration with), which works very well.
As for features, we've argued this before at length, but my opinion still stands that features are only valuable if used, and only in the games in which they are used. For example, I like Steam Remote Play, but given that I use it a handful of times a year it's in no way a determining factor for where I buy my games. The impact is minimal. And third party software generally tends to work better for most things (whether that's MMO raid management, in-game voice/chat, or most other stuff), which generally doesn't need platform integration at all. The main function of a game store/launcher is and continues to be the ability to buy, download, update and play games, which EGS does excellently, and it thankfully has the most central add-on feature (which relates directly to core gameplay): cloud saves. Beyond that, store/launcher features are mostly optional, variable from game to game, and complexly interwoven with other third party services. Thus, unless there is a glaring omission (a lack of cloud saves would definitely be this), I don't see the problem with buying games across stores.
I mean, you can argue that EGS lacks features just as you can argue that Steam's UI (and especially the overlay) are hopelessly dated and impractical. Both are true, and neither is a deal-breaker to me. They're just different. And more options = more betterer.