There's no single legal number, but there are practical guidelines that reflect how much we actually rely on power today compared to when many homes were originally wired.
With TVs, entertainment systems, lamps and charging devices, most living rooms benefit from at least 4-6 power points spread across different walls.
Two to four power points is typical, accounting for bedside lamps, phone charging, and larger items like a TV or desk setup.
Kitchens usually need the most, benchtop appliances alone (kettle, toaster, microwave, mixer) can require 4+ points on the benchtop circuit, plus separate points for the fridge and any built-in appliances.
Homes wired in the 1970s-90s were designed around far fewer appliances than the average household uses now, which is why double adaptors and power boards become a permanent fixture rather than an occasional workaround, itself a sign more power points are worth adding.