When planning my trip to Barbados, flights from Dallas were expensive. Google flights really came through with the cheap flights. It looks for the cheapest one way ticket going and coming. It is very likely you could be on different airlines coming and going, but you can save a lot. Instead of flying straight from Dallas, it was cheaper to get a flight from Miami. I saved about $200 getting two different flights than then flying straight.
If you are looking for convenience and don’t mind spending the extra money this is not your best option. For me, I wanted to save money and it worked out perfectly. Barbados was just one of many flights I had to get and I wanted to save where I could. When you get to google flights websites you type in your the dates and locations and google will give you the cheapest flights.
One advantage I had of using google flights is being able to have a few hours in Miami. So on my way to Barbados, I had a mini trip. We decided to go to Miami Beach during our layover. We had a few hours but by the time we took a few pictures and got something to eat, it was time to head to the airport.