One reason the Roman Catholic Church will outlive the JW org has to do with their respective origins.
The RCC had contrived a link with Peter and therefore claim divine approval according to the scriptures which they themselves made sacred (clever trick!) In doing so they are so wealthy they have become an independent nation called Vatican City with a monarchical head of state, the Pope.
The JW org on the other hand, which has had to periodically change its name and doctrines, have to constantly disown their origins. Systematically they have had to disinherit their former beliefs and leaders which is like periodically cutting off one's own feet!
Russell distanced himself from the date-setting Miller as well as the others who started the Watchtower with him in 1879. Russell had promised a paradise on Earth by 1914, living just long enough to see his hopes dashed. Then Rutherford taking hold of the reins of glory built up by Russell's reputation, increased the JW empire on sales of dire books. He dismissed Russell's failed prophecies with failed prophecies of his own--such as Armageddon by 1925 and "Millions now living will never die". Another go-getter Knorr replaced him with his personal theologian Fred Franz proclaiming 1975 and the generation which saw 1914 would see Armageddon. All dud fireworks. Now Fred Franzian religion is wrong; type/antitype was all hooey. The latest attempt at running the Watchtower cult relies on wearing blinkers, not thinking too hard and obeying even if you don't know why you're doing it.
Unlike the RC Church, the JW religion does not have a solid foundation, it is on a conveyor belt, ripping and fraying at the edges, out of date and breaking down.
When you have to sell of a lot of your property assets in a business, you know your time is up.