There is a guitar learning system known as CAGED that has similarities to Echo Alpha Delta. CAGED opened the door to visualizing chord shapes across the fretboard, and many players have learned from it. There are a number of reasons why Echo Alpha Delta is an improvement, for all skill levels.
CAGED has a fundamental limitation that needs to be addressed. The chord shapes are still named after the open-position pitch they originated from. When a player puts on a capo or forms a barre chord and uses one of those shapes, the pitch name of the shape no longer matches the pitch being played. Play an A shape at the 4th fret and you're voicing a C# chord, but CAGED still calls it the A shape. The shape name and the pitch name collide. This is the central reason Echo Alpha Delta exists: to decouple these crucial shapes from pitch names, so they can be put to use more intuitively.
Take a look at an open C chord and you will see a Delta shape sitting at the top of it. An open G chord has an Alpha shape in the heart of the chord and an Echo shape at both the top and bottom. Two of the five CAGED shapes are composites that already contain our three shapes within them. Echo Alpha Delta is not missing anything; it is distilled.
As each shape expands to hold every chord quality and every scale, the learning load multiplies. Three shapes is already a significant commitment, and as we see in the book we can reach any chord or scale with these 3. Learning 5 equal grips involves two-thirds more information for no additional coverage of the fretboard.
Beyond the new names, each shape has its own character and assigned colour: Echo is blue, Alpha is red, and Delta is green. The colours and descriptions are deliberate memory aids, designed so the player can internalize the map away from the instrument and project the three shapes onto the fretboard at all times. If the player can get a memory foothold with this map, they can use it as a platform to play better.