Why would games need their own launcher?
Just install the damn game, ask if you want icons on the desktop as well as in the start menu.
OS handles it all for you.
Perhaps some multiplayer functionality and such makes sense to share cross-game, but I miss the bad old days of every game having a bunch of privately maintained servers and its own server browser list etc. You could eventually find a few servers that fit your playstyle and make online gamer friends that way.
The only benefit steam brings to the table as far as I can tell is making it easy to reinstall your library on a fresh PC.