You need both.
Recently, I heard Shaan Puri talk about this in a conversation with Noah Kagan, founder of AppSumo. He said that success is the result of what he calls "persistent adaptation". A commitment to shipping our work regularly. Doing. Trying stuff out. Learning. Adapting to the new information.
It's not enough to merely persist and endure. Doing the same thing again and again, expecting a different outcome, will most likely take you nowhere.
To truly succeed, you need to persist AND adapt.
What’s no longer true? Okay, now what?