Travelers are not required in leisure sailing but they still may add plenty of comfort, eg. allowing for sail trimming from the position of the helm
(in two helm
boats and in very beamy boats - if the sheet exits at the traveler). Also, you can move the sheet to one side of the boat and keep the center clean for traffic, etc.
In normal sailing, the traveler improves & simplifies sail trim. You can dump the boom to the lee in a fraction of a second with a traveler, not so with the sheet, so it is essential for fast and responsive boats in gusty conditions. In a very beamy boat you can also do without a kicker
- provided the top is square to allow for opening of the top portion of the main.
BTW To keep the main off the spreaders you normally trim the kicker
, not the traveler. Then again, running and on the broad reach the main will be on the spreaders to some extent (and depending on which style of spreader angle you opted for).