Agility: the ability to move about quickly and easily.

Specially in times of uncertainty… when problems and solutions both are or one of them is unknown… and the ability to move quickly is paramount.
People do the work, not processes; therefore, agility rests on people.

The Agile mindset (doing Agile and being Agile) assumes that knowledge workers are already doing their best.. and that the power of agility is though people: their ability to self-organize, their improved relationships with one another, empowered, intrinsically motivated, and them having positive work environment.
SAFe Principles #8 and #9 support knowledge workers.
Embrace and employ these principles and get ready to experience the power of agility through processes people.
Unlock the intrinsic motivation of knowledge workers
— SAFe Principle # 8
Decentralize decision-making
— SAFE principle # 9