Didn't we already have this thread?
Sometimes it will decide my internet is down, yet inside steam I can still play a ubisoft game that talks to Ubisofts drm server. Umm ok, and oh look I can bring up steam store in a browser just fine,
Sometimes a game just won't run up. OK quit steam, force quit the app that has not yet booted, rerun steam try again. No luck? Restart my computer, rerun steam, try again? No luck, /shrug try later, try tomorrow.
Yes sometimes it does indeed run for weeks with zero issues.
I buy stuff from the app store and steam depending on my inclination, certainly their is no equivalent of the steam sales on the app store, but that does not change the fact that on any given day I don't know if steam will work, it just mostly does.