I don’t understand your point here. I did mention in my comment that I was talking about the world's professing Christians. Do you have evidence that amongst the world's professing Christians the idea that the Earth is young but God created it to look old is mainstream? As far as I know this is a fringe idea but I haven’t been in tune with Christian thought for 15 years so things may have changed.

i actually misremembered that statistics -- it was that ~40% of americans explicitly believe in young earth creationism. young earth creationism is definitely a mainstream view nationally in the US. even if the level is half that globally among protestants it would qualify as mainstream. protestant denominations (particularly american fundamentalist ones) are also growing at a much faster rate across the world than catholicism.

"A 2017 Gallup creationism survey found 38% of adults in the United States held the view that "God created humans in their present form at one time within the last 10,000 years" when asked for their views on the origin and development of human beings, which Gallup noted was the lowest level in 35 years."

and according to this[1], globally 50% of protestant leaders are biblical literalists (generally associated with young earth beliefs)

[1] http://www.pewforum.org/2011/06/22/global-survey-of-evangeli...

> ~40% of americans explicitly believe in young earth creationism ...... God created humans in their present form at one time within the last 10,000 years"

Those two are not the same thing! That's the entire topic of this thread!

> young earth creationism is definitely a mainstream view nationally in the US

Your data does not back up that sentence.

> are biblical literalists (generally associated with young earth beliefs)

Again, not necessarily.