MysterD: I think if dev's/pub's want to port games b/t stores easier, they need to go less proprietary from the jump.
DoomSooth: I've been saying this for many years but most everyone has a throbber for Steam. Developers and publishers go where the money is. They know most users don't care about playing offline, offline installers, or backing anything up. Nothing will change that unless something catastrophic happens to Valve.
It's ultimately on the dev's and pub's, in terms of features for games, no matter where they put them. If they want to, they can build Achievements and features into the game so it works offline and with offline profiles - like games did before Steam. If they want, they can disable Steam-Stub DRM or any other non-sense, when need be - once the game's old and often dirt-cheap in sales and/or in Bundles.
Steamworks is normally only on Steam-versions of games only, unlike EOS.
EOS is allowed to be built into games, as even Modern TR Trilogy (TR 2013, Rise, Shadow) supports it on Steam - but honestly, I don't trust Epic's EOS b/c it's an online-suite either. There were problems once Modern TR Trilogy added EOS to it...and many couldn't get their Steam-game working without it; of course, that got fixed fast b/c of the problems.
There are DRM-FREE games on Steam and Epic - need more games to go that way, especially if and when they get old.
It's probably gonna take Steam, Epic, Origin, UbiSoft, or someone going out of business and for more gamers using Steam Decks, ROG Ally, and/or portable laptops or handheld devices and not always have Internet access...for gamers to wake up to the problems of online-services.