Not every business needs to outsource the whole thing. Sometimes you already have a marketing team, an agency on retainer or a developer who can execute; what is missing is judgment: what to prioritize, what to ignore, and how to tell whether the work being done is actually worth it.
As an SEO consultant I sit on your team's side. I review what you have, define the strategy, leave the roadmap in writing and support execution with recurring sessions. You keep control, and the knowledge stays in your company instead of at the agency.
It is also the right role when you want a second opinion: if your current provider reports a lot of activity and you are not seeing customers, an independent review quickly clarifies whether the problem is the SEO, the website or the offer itself.