JWs are not preaching the message that the bible indicates would be preached. Let me give you 2 examples from the bible
1. Revelation 12:17 describes christians as bearing witness to Jesus. There are other verses in Revelation which also mention christians bearing witness to Jesus. So Revelation indicates that christians would primarily be witnesses of Jesus - not witnesses of Jehovah, not Jehovah's Witnesses. The very Jehovah-centric and christ-diminishing Jehovah's Witnesses are not the christians that Revelation and other NT books speak about.
2. The question asked by the last days ridiculers' at 2 Peter 3:4 implicitly reveals that the presence of Jesus would start in a very visible and climactic manner. It also reveals that the presence does not begin with the start of the last days, like JWs teach. If that were the case, the ridiculers, as they are living in the last days, would also be living during the presence while foolishly asking where is the presence. But Peter does not say the ridiculers are foolish for not knowing that they are actually living during the presence. Nor does Peter say they are foolish for not knowing that the presence started invisibly. Conclusion: the ridiculers' are only wrong in doubting that the presence would come. Their implicit understanding of the nature of the presence is correct. So where did these ridiculers of the last days get their understanding of the presence? Who preached to them about the presence? Was it JWs? Obviously not, because the presence JWs are teaching is different to the one that the ridiculers and Peter speak about.
So the focus of the preaching work of JWs is off. The focus should be on Jesus - his sacrificial death and resurrection and salvation by faith in him. This is actually the most important facet of the good news of the kingdom. Because it is accurate knowledge of, and faith in, Jesus that would give someone salvation - not knowledge of, and faith, in a heavenly government. A person can have all the knowledge of the kingdom govt. and if they lack faith in Jesus they will not be saved. But a person can have all the faith in Jesus and lack knowledge of the heavenly govt. and still be saved. JWs foolishly think the good news of the kingdom is mainly about preaching about paradise earth and a heavenly govt. But it's actually about salvation and inheriting the kingdom by means of faith in Jesus. And JWs are, and always have been, teaching a false eschatology. JWs match the false prophets Jesus warned about at Luke 21:8.