Why Freetown anchored South Atlantic operations

Where were British South Atlantic forces mainly based?

Primarily at Freetown, whose location and infrastructure were more useful than Simon's Town or the Falklands.

The answer places most South Atlantic basing at Freetown in Sierra Leone. Simon's Town could be used, but its position was too far south for much of the theatre. The Falkland Islands did not possess the repair, supply, and port infrastructure needed to serve as the main hub. Brazil was a foreign state rather than a dependable British base network. Geography and existing facilities therefore made Freetown the practical center of operations.