Your dad is right to not understand that. There is zero reason for any appliance to take longer than a second to turn on from zero power. Even complex systems can use fast boot techniques (i.e. hybernation) to power on quickly without any power draw while idle. All it takes is developers who care and/or consumers who demand better.
Ans that's why devices have standby from which they wake up instantly. That's the technique you're talking about.
If you stubbornly decide you're smarter than that, then wait I guess?