but after all this is the Private Flying Forum.
Absolutely!
It is only when you get to fly powered aircraft, that the application of power is also required.
The application of power is possible, not required. Yes, if you want a power plane to maintain altitude, or climb, you're going to need power. Otherwise, if you're prepared to accept a constant net descent as a part of your maneuvering, power is not required, fly it like a glider!