What an absurd argument in order to impugn the power of Scripture. For this to be valid then you would have to show that the prevalence of the Bible translated into the vernacular has not historically correlated to an increase in the Christian faith, which it has, and is in places like Africa (see above post by God's grace). And that those who esteem Scripture most strongly suffer the greatest decline, which is contrary to reality. And "sustainably" must be defined as only beyond 200 years.
Meanwhile, to support your alternative, you must show that the current decline in Christian faith in countries in which the Bible has been translated into the vernacular is in contrast to Catholicism, but which it has not, such as in Latin America . And despite immigration from there into the US, .
A report released Tuesday by the Pew Forum finds that the total number of Catholics in the United States dropped by 3 million since 2007, now comprising about 20 percent - or one-fifth - of the total population.
And perhaps more troubling for the church, for every one Catholic convert, more than six Catholics leave the church. Taken a step further, Catholicism loses more members than it gains at a higher rate than any other denomination, with nearly 13 percent of all Americans describing themselves as former Catholics.
The big winner in terms of growing numbers is the unaffiliated, or the so-called nones, shooting up to about 23 percent of the total population from just 16 percent seven years ago. The 56 million adults not belonging to any faith tradition outnumber both Catholics and mainline Protestants; only Evangelical Christians comprise a larger share of the population.
Big demographic shifts within Catholicism continue to change the face of the church. Hispanic Catholics now comprise 41 percent of the US church, up 6 points from 2007. And the average Catholic is getting a bit older, with the median age of 49 up four years. Immigration from Latin American countries has kept Catholic number stable in recent years, and 39 percent of American immigrants are Catholic. -https://cruxnow.com/church/2015/05/12/pew-survey-percentage-of-us-catholics-drops-and-catholicism-is-losing-members-faster-than-any-denomination/