Pillar-cluster vs a single fat hub page — depends on search volume

Pillar-cluster vs a single fat hub page — depends on search volume
Client wanted 'one big ultimate guide'. The topic was too broad for it.
— Single fat hub: one URL, all the rank concentrated, simple. Wins when the topic is ONE intent that doesn't split into sub-searches.
— Pillar + cluster: pillar targets the head term, clusters target the long-tail variants, all cross-linked. Wins when people search 20 distinct sub-questions.
The move: I pull the keyword set first. If sub-topics each have real search volume, they each get a page that links up to the pillar. If they don't, I fold them into one hub as H2s.
Don't spin up 15 thin cluster pages for sub-topics nobody searches — you'll just dilute the pillar with starving children.