OTD is not 20 years old, jews have been going OTD since the days of the Golden Calf.
It did reach its heyday in the 19th and 20th Century due to external factors in the greater world (The Haskallah was just basically piggybacking on them). That 80-85% of jews are not religious today is a testament to that factor
There isnt much difference today than there was 150 years ago except because of technology we are more aware of things outside our normal sphere of knowledge. There is a video from 1933 from Munkatch of various scenes from Munkatch and one of them is the Munkatcher Rebbe giving Tochacha to american jews for not keeping Shabbos. You can see the video on Youtube.
If you think most are coming back, you are probably only fooling yourself. Most do not come back and unless we are willing to admit to ourselves why the left in the first place , not much will change