AEDs are present in a lot of public-space first aid supplied these days: supermarkets, shopping centres, etc. When you turn them on, an automated voice guides you through every step. They're not idiot-proof, but they're pretty close.
Don't quote me on this, but I think AEDs are quite pricy (I think in the range of 10-20k USD). They could totally be on an emergency kit if you or your organization has billionaires but otherwise are better utilized in common places.
When I worked as a lifeguard in high school (2003-2006) at the high school indoor pool we had an AED that hung in a box attached to the wall.
If I recall, I think we practiced with a dummy one during lifeguard training, but they are more ore less automated and a voice walks you through the process. I think most people would be able to use one successfully, without any prior training.
Without looking at the statistics, I wonder how many lives can be saved if there are enough people trained to use AED and provide CPR considering in a lot of areas it can be a while before ambulance shows up