Water pressure is mostly determined by the size of the water main to the house and the size of pipes thereafter to the fawcets.
I like the 8 inch round shower head I have with a water restricted. I get hair washed fine and clean up well. I honk you need the large shower head when there is a water restricted.
Yes these things do matter but are necessarily the major contributors to water pressure.
The main impact on water pressure for most urban dwellers is the height of the water tank that supplies your area, the distance your house is from the tank and how many users there are between your home and the water tank.
Many older neighborhoods have seen water pressure drop as more homes have been built in the neighborhood. More people drawing from a main that was sized to service far fewer homes lowers water pressure.