I got set for my son after noticing he loves stacking Jenga blocks and generic Kapla gets 10x more usage than Lego.
Can it be that the moment Lego moved from mostly bricks to custom single use shapes for every kit the joy of combining them died? My kids build car, Dino, Harry Potter set once and then gather dust. Bridges, castles, towers and roads from Kapla get rebuild every day.
When I was young there were fewer types of shapes but a lot of new sets contained a lot of such specialized shapes. I rather played with the lego i found in the attic.