No, but its important not to rule it out entirely, which is attitude I used to have, which I have since changed. Agents often allow full flexibility by cancelling flights and crediting them to a new flight, allowing a lot more freedom than the independent route. I know I saved a lot of money and was able to double my time in South America purely because I booked through an agent. It costs an extra $100 USD at the time but I changed the flights 4 separate times to extend dates, change destinations.. well worth it in that regard