Beach town drains have their own problems. The older cottages near the pier have been collecting decades of everything, and when a drain out here clogs, gets snaked, and clogs again a few months later, that's not bad luck. The snake did its one job, it opened a hole through the blockage. But the grease, soap, and buildup coating the pipe walls stayed behind, and it closes the hole back up over time.
Hydro jetting actually clears the line. A high pressure stream of water scrubs the pipe walls the whole way down. It strips years of buildup off instead of drilling through it, and flushes it out of the system.
Does every clog need jetting? No, and you'll hear that when it's true. Plenty of backups are one time events a snake handles fine. The contractor evaluates your actual line, explains what they see in plain English, and gives a straight recommendation. The decision is yours, start to finish.