Some large OEMs with the resources to do the design effort could use a large passive heatsink on even surprisingly late processor (i. e. Pentium 4) because they could make a holistic design with shrouds and baffles and know you were getting just enough airflow from a case fan elsewhere to keep the CPU within spec.

Early ATX designs, in fact, were often based on "the PSU has its fan placed so that it will draw air over the CPU heatsink and out the back"

Enthusiasts, obviously, went for brute force designs.