Am I totally nuts or just a bit off?

A few weeks ago I came across about a hundred old mono pop jazz albums from the fifties in storage I had forgotten about.
Had some extended(3am extended) listening sessions using a Shure M78 S(sperical) tracking a little over 2 gms on my trusty Sony PS-X7 .

Sure seemed to me that mono was way cool especially in the LOW listening fatigue factor. Going on a Goodwill road trip next week-LOL,

Tell me again, why was stereo invented?