"The 4 pin is optional.
Through a 8 pin connector you can give up to around 300-350 watts to the VRM (then circuit which powers the processor). A Ryzen 8 core processor will peak at around 150-175 watts, and maybe have brief moments - like milliseconds- when it uses up to 200 watts.... so nowhere close to the maximum possible.
The 4 pin connector is there more or less in case someone would want to use the motherboard to do some extreme overclocking, with very high voltages and LN2 or other super cold liquids.
For regular usage, adding an extra power cable in the 4 pin connector wouldn't make any difference."