Indeed, SAFe fails to address what actually leads to agility: organizational culture, which is simply the ways that people feel they are expected to respond when situations arise. Those expectations are set by the behavior of managers. It's really that simple. If you improve the culture, and challenge your people to improve their processes, they will do it - they don't need SAFe. Using SAFe is an attempt to take a shortcut. It doesn't work. It won't give you agility. It will likely actually get you to release quarterly, but then slow you down and gum things up.