I didn't use YouTube as my information source, but in relation to the number of transgender people out there, thousands is still amazingly low. There are 1.4 million transgender people in the US alone. If you calculate your YouTube numbers (assuming they were all US [and unique cases, not repeat videos]) 1,000 cases gives a ratio of less than 1 person per thousand detransitioning. 2,000 videos would amount to less than 2 per thousand.