I really would like to see statistically supported numbers on usage of the whites on the long term that I presume would be the "numbers" you refer to. I really have not seen any "numbers" that could be relied upon to establish a long term trend of usage. Yes the number of 4K applicants has gone way up and popular day hike routes to 4Ks are mobbed but head out into the non 4K areas and I dont see crowds on the trails. On many non 4K trips I rarely see anyone even on popular weekends where I have a tough time parking. Once I turn off a 4 K route, it gets real quiet. Most of the time about all I see are a few trail runners. The numbers I typically see are short term used to support or refute some project. I do see day use crowds on popular day hike routes to 4 ks have gone way up. My usage during peak times has decreased so perhaps this has changed my subjective views of usage. I do remember quite vividly one summer weekend in the late seventies climbing up Tucks to the summit and it being almost a steady line from Pinkham to the summit. It was particularly in focus when climbing the headwall and looking back down. the trail and seeing what a line of hikers with at best 10 to 20 foot intervals between the groups.
Subjectively, in the last few years I still see a decreased overnight use of the backcountry other than very specific sites like Guyot or other AT sites. Even in non wilderness areas where the 200 foot does not apply, when wandering around in the woods off the trails I find evidence of past campsites and fire rings that used to get a lot of use at one point but have far less use now. I on occasion can date the use by looking at the occasional old fashioned pull tabs or fire rings and the pull tabs themselves. I cite Thoreau Falls trail, particularly along the stream at the upper crossing. lower Shoal Pond trail and multiple spots along Moriah Brook trail that look like they were heavily used and abused 30 or 40 years ago that are slowly recovering and get far less use.
I will agree, use has shifted and day use of the 4k trails has exploded but during the roughly 2 years pre Covid that I was hanging out with "redliners" (pre name change) doing more obscure trails. I saw lots of evidence of far less trail use where bootleg sites and scarred trees are growing back in, trails are growing in and blowdowns are far more evident than in the past. Sure, some of it may be less trail maintenance, but it is also less usage. Plenty of trails in the Evans Notch area especially the Caribou Speckled wilderness are very difficult to follow despite evidence they were used far more in the past.
In general, my experience is if I want to see crowds I know where to find them and if I do not want to see crowds, I know where to go. IMO, 5% of the trails are getting 95% of the use.