YOu did provide some really good photos for what has to be the most common reason our cars suddenly leave people stranded. But we call that the "Mystery No Start". It was documented here fourteen years ago and DJ become the defacto "go to guy" for those not willing to learn to solder just to fix their car.

Skillfully crafted clickable link

As our cars have aged, it has been learned that the engine control relay, traction control relay and fuel pump relay are also prone to two failure modes: open coil and pitted armature contacts.
For $65 or so, DJ reflows the solder and changes the three relays (maybe more relays, not sure). He just did mine when my engine control relay coil failed.

The current advice is to have your RCM reworked by DJ as a precaution and most of us 9 (myself included) carry a spare RCM. Mostly because an open relay coil is a real pain when you are 50 miles from home and have no rubber bands with you to hold the relay closed.