‘ And the children of Israel served YHWH all the days of Joshua, and all the days of the elders who outlived Joshua and had known all the work of YHWH, that he had wrought for Israel.'
This summary verse confirms that during the life of Joshua and his near contemporaries who had seen the great works of YHWH in Egypt and in the wilderness, the people remained faithful. The elders, who remembered the past, were the father figures in the tribes and sub-tribes, and they ruled well. They kept apart from the Canaanites and worshipped YHWH only, maintaining the covenant faithfully, attending at the feasts at the central sanctuary, and living by His Law under the guidance of the priests and Levites, although there were always going to be exceptions. Thus the book finishes with a declaration that Joshua left things in good order, and that things seemed well.