Miami is many small markets that happen to share one airport. Coral Gables and Pinecrest have houses on big lots, often owned for decades, and their sellers ask careful questions before they call anyone.
Coconut Grove and Key Biscayne are waterfront, so sellers worry about flood zones and insurance and want an agent who can talk about both. Brickell and Miami Beach are mostly condos, and the buyers may live in another state or another country.
People in all of these places search in English, in Spanish, or in both. Zillow, Realtor.com and Redfin are where sellers look up agents and compare them. You will not beat those sites for 'homes for sale in Miami'.
You can win the searches that name one neighborhood and say 'sell'.