It is kind of neat just how little power some of these older systems used. A big part was it was cheaper to make processors that used non-ceramic caps on them -

It is kind of neat just how little power some of these older systems used. A big part was it was cheaper to make processors that used non-ceramic caps on them - but it limited the amount of power they could use due to thermal dissipation limits. A good example in a similar fashion is the Super Nintendo. The power supply is rated to 7.85 Watts but it only uses roughly half of that when running. I believe the Neo Geo used 5 Watts peak. And these aren't physically tiny machines like a Raspberry Pi.