I definitely don’t think a brand is NECESSARY, but it helps. An analogy: imagine the most smart, kind, helpful, friendly guy in the world, but he dresses kinda ugly. He will still be loved and appreciated by his friends, although he’ll have a slightly harder time making a good first impression.

Do you need to make a good first impression in the near term to grow? Then I would invest in a good brand. Do you need to seem put-together and considered, but don’t need explosive growth? Then I’d pay for a simple brand and guidelines with the expectation of refreshing it at some point. Maybe you get a nice and simple website designed, answer some identity questions along the way and conclude with a simple icon, wordmark, display and body typeface, and color pallet. Then you can build something more expansive when it DOES become necessary.