There are stages in an agency's life when it's going through serious changes or transformations. It often happens in the earliest stages, during the start up phase, but it may equally come along if you decide to reposition, to enter a new market, or to do a full pivot. At times like these it's important that you have an engine that drives the changes through the business, something that brings alignment across the company so you're all pulling in the same direction, and an extremely tight focus in your efforts so nothing's wasted. There's often so many possible things that you can do that's it's hard to work out what to do, and things can easily become a bit chaotic and haphazard.
OKRs can be that engine, helping you with that focus and alignment, and also giving you ways to learn quickly as you adapt. To get those benefits at this stage, though, you may need to fairly directive in your implementation.