What? That's not a statement on the most effective, that's a statement of current strategy. Which may be all that is practical given current resources.

Which per your source is the case.

vaccination based on country-specific epidemiology, burden of disease, cost-effectiveness, feasibility, capacity and resources.

But scientifically the best way to protect most of the population is to vaccinate as many people as possible. This provides protection to people that are unable to be vaccinated due to other health conditions.

Like come on you didn't even understand what you posted