The Iroquois were very much relevant until the Revolution. By 1648 they hadn’t even yet gotten started really. The height of their military power was about 1650-1666.
From that point on the Oneida had a different sort of outlook on New York and New England politics, tended to side with Americans, AND, most importantly, developed an immigration policy that allowed skilled white folks to live on Oneida lands.
This was consistent with the Brotherton policy of assimilation ~ and the Brotherton's ended up moving in with the Mohicans on Oneida and Onandaga lands.
Whites and blacks continued to pour into the British American colonies and could not be effectively challenged after that time. That didn't mean some didn't try, but they lost!
The inescapable lesson was that the Indians could not hope to continue with their traditional hunter gatherer way of life. They had to change and yield to a more powerful people whom the Indians feared and in great measure scorned.
In the cruel way of the world, between different peoples, land belongs not to those who claim it or who live on it but to those who have the power to seize and hold it.