A religion that started in 1914 similar to JW's with millions of adherents!!!!
Funny, but I don’t recall reading any article in the Watchtower or Awake! magazine about this “Iglesia ni Cristo” religion. Perhaps the WTS wouldn’t want to write an article about a religion that is so similar to the JWs just in case some people might begin to see the parallel and connect the dots. (Some might think that Jesus’ selection of his “true” organization wound up resulting in a tie.)
Most of these religions that started around the same time either evaporated and disappeared or else grew to a large enough size that they became self-sustaining.
At a certain point, enough people will keep believing something even if the founders all stood up and said "yeah, sorry - we made it up". People certainly won't believe damning evidence that they made it up.