I love randomness. Controlled randomness is a concept I created to describe randomness from a selected pool of information. Uncontrolled randomness becomes less and less useful as the quantity of information grows.
Take Wikipedia’s random article option for instance. The likelihood of getting a result from your categories of interest is very very small. Controlled randomness in this case would mean being able to select your categories of interest and generating random articles only from this information pool.
In Obsidian, the randomness option could be contextual.
Random note from folder
Random note from current tag selection
Random note from all visible graph nodes