Many were willing to become indentured servants because it offered the possibility of land and by default freedom once they were released from their indentures. Obviously, if they were willing to become an indentured servant that life was preferable to the conditions they had in England. Life was not easy, and many found it difficult to satisfy their indentures, and of course once the need for labor exceeded the ability for landowners to entice indentured servants, many turned to African slavery to fill the void. Still, the American frontier was filled with those who had earned their freedom through indentured servitude.
Let me add that although elections to the House of Burgesses were always relatively democratic, from that body’s founding in 1619, no one who had been an indentured servant and no one whose ancestor had been an indentured servant was elected to the Burgesses in the 17th century. The way up from indentured servitude was difficult.
In fact, the Virginia Company lamented in Virginia’s earliest days that so many recruits to live in its colony returned to England as soon as they could. Life proved harsher than expected.
Besides that, Prof. McClanahan in his answer may inadvertently have given the impression that land awaited indentured servants at the end of their servitude. This is false, at least in regard to Virginia. There, the law required that they be given seed, farm implements, and a new suit of sex-appropriate clothes at the end of their servitude, but it seems that most never became landowners.
By the time of the Revolution, there were people in the Virginia political elite who descended from indentured servants, notably the eminent Edmund Pendleton, who was an uncle of John Taylor of Caroline and distant cousin of James Madison.
Let me add that many of the participants in Bacon’s Rebellion of 1676 were former indentured servants who were unhappy with the political situation in VA, as Kevin suggested, and while they were not promised land, they could squat on it, and many did.
And, while not an indentured servant in the VA model, Benjamin Franklin was indentured to his brother. He later broke those indentures and ran away to Philadelphia.