Seems people are sick of Christi-SCAM-ity in all its forms. The cat lick church is losing members sick of hearing about how they are sinners and jesus is needed for their salvation. That was behind the jokehovian witlesses growing so much in the mid and late 1980s. During that period, people were looking for an alternative, and that was what was available. So, many joined. Almost a fad.
Then, along came the Internet. People realize that the jokehovians are no better than the cat lick church, and in many areas much worse. Anyone looking for an alternative these days can just take the washtowel littera-trash and spend about 20 minutes of research on the religion to scratch that off the list. So, they go down the list of xian religions, and find them all flawed. With that scratched off, they look at the other options. Judaism does not appeal to Gentiles, by and large, with its equally strange teachings (such as keeping kosher and not operating a switch during the Sabbath). Islam is what's left, and many end up trying that. As Islam is different from Christi-SCAM-ity, many will stick. Hinduism is also off the beaten path enough to get people interested, but the xian corruption of the original Hindu is enough to prevent real spirituality. Wicca also appeals to many--again, this is watered down by xian corruption.
At which point, those who skip Islam often become atheists. Some will stay there. Others will research the ancient religions. Still others, tired of all Abrahamic religions, will think "If joke-hova or allah really push poverty and sexual repression, I will give Satan a try". The truth is, when the books are uncooked and the bogus numbers among the jokehovians are fixed, spiritual Satanism is actually growing faster than the jokehovians which goes against humanity and nature.