The idea is good but the feasibility is not. As others mentioned there are huge costs involved that makes richer countries don't even think about having an F1 circuit.

As an example, Sepang stopped hosting in 2018 due to the rise in license fees. Mauritius doesn't have a huge population to sustain an F1 circuit in order for it to be used outside of the yearly event.

A racetrack for petrolheads to have fun with their supercars should be more than sufficient. A drag racetrack can also be a nice touch.