There are 2 4069's required for the schematic.
One way to evaluate the relative "simpleness" of a circuit approach, especially for an amateur building a one-off home or school project, is to count the number of soldered pins. For digital logic, this includes all power and input pins, but not any unused output pins.
Not counting the switch and the LEDs and their current limiting resistors, which would be a constant part of any approach, the circuit in post #6 has 124 soldered pins. A circuit with a switch conditioner, 4-bit counter, and 4-to-16 decoder would have 55 pins.
ak