Depends on how decline is defined. On the one hand, based on one definition SBF shows numbers compared to other religions declining in numbers. On the other hand Nicolau shows a decline maybe not in overall percentages in growth but in other ways. For example when you go to a convention and not many people get baptized compared to the golden years. Also, everybody thought that the number of anointed would decline and non-anointed would take over the gb but there is no short supply of younger than the other sheep and the great crowd anointed. —And the end did not come within the expected Biblical time frame. Also, the 1914 generation of people linked to the JW preaching work died so what was the point of the preaching work if their rejection of the kingdom message was in fact inconsequential as it relates to them. Obviously it was important to those that became JW. But now it appears that the preaching work is unlinked to 1914 and applies to a new generation of humans not contemporaries or related to 1914. The generation teaching, the end of the 6000 years and the beginning of the Millennium, the great tribulation have not materialized—JW are all in waiting for something to happen…..
Concurrently, JW have a relationship with God that they enjoy. So as much as JW are waiting and groaning for relief, even if nothing happens, they are still convinced that it will happen. They won’t lose faith because their relationship with God substantiates their beliefs. This is how JW think.