A bathroom where you might use a hairdryer or other high
consumption device would require more latitude.

Bathrooms, kitchens and laundries require 20a dedicated circuits (2) in
kitchen.
The original question was about the general lighting circuits. In the US these
are distributed equally based on the VA per square foot (3va) and the
receptacles are placed based on the average length of a lamp cord (6 feet). The
objective is not to have any wall space 2' or longer, not more than 6 feet from
a receptacle and that no cord will have to be pulled across a door opening or
other hazard.
There is no limit on how many receptacles that is since they assume you will
not really use them all anyway. It is purely based on the projected load of 3va
per square foot.
This is just the minimum. You can always put in more.
We plug in a lot more things than our parents but generally they use less
power. Large loads are usually put on dedicated circuits.