The most powerful memory technique in the history of mankind

Well, that's a clickbaity title...and...it's about memory palaces, so, fair enough. Extremely short article though. (350 words)

I help people improve their memory because mine used to suck.

That illustrates a point re genius/talent/training - people often end up a champion at something because they were bad at it, not because of their natural skill.

I thought spaced repetition was a more powerful technique

What about people with aphantasia?