Idk if this is “a reason” but leaving the launcher running without actually playing the game does count as playtime for steam, which may result in folks not being able to refund it if they don’t like it, and increases overall hours played.
Whether that’s part of why these games have useless launchers, or whether those things actually pan out that way, who knows.
That's just a by-product of how Steam works. Playtime is counted as long as the Play button says "Stop".
For games without DRM (e.g. KSP), you can launch it from the Steam install folder without Steam running. Everything works perfectly but your playtime won't be counted for the same reason.
Maybe, but for Civ 6 specifically the launcher came out a few years into the game's lifespan, so I'm not sure they were doing it for whatever marginal revenue benefit that would be. I imagine selling DLC without Steam or whatever storefront getting a cut might be a motivating factor.
https://store.steampowered.com/app/1295660/Sid_Meiers_Civilization_VII/
