I'm not really surprised by any of this, in fact I actually think sexlessness is even more prevalent than what we are seeing on those stats.
I'm a bit older, 30 years old, and a significant number of other men I know who are plus or minus a few years my age fall into one of these 2 categories if they are not in a serious relationship or married.
1. Men that rarely date and have virtually no sex life. Some of these men are what you'd picture when the word incel comes to mind, out of shape, not very attractive, etc. However, I know of a lot of guys who are otherwise normal looking guys that fall into this category, ranging from average to even attractive. These are normal guys, meaning they have personalities, work, are at least somewhat normal socially, etc.
2. Men that sleep with tons of women. Some of these guys are attractive but I've also met and know of several that aren't good looking at all. There is one guy I know who is a slayer and is the polar opposite of this chad nonsense. He is a 25 year old from India going to university and is around 6'tall and quite overweight. I think men like this have a combination of certain personality traits with simply being in the right environment to meet tons of stupid women.
I can't say what the exact reasoning for all of this is by I feel it is due to several different factors. Many women are super delusional today and have literally no clue. I'm 6'4" and lift regularly and seen no results at speed dating events with barely average women, been rejected by 4s at a bar, etc. I haven't been on a date in about a year and the last sexual activity I had was with a higher end escort back in February. I can't imagine what it's like for your averageish guy out there if I struggle.
You think some average but decent guy out there who is getting no matches on tinder and gets rejected constantly by women that aren't even that cute is going to have the desire to keep trying? Stuff like this is draining on your self esteem and mental health and there is only so much one can reasonably take. Logically these men are devoting more of their time to things like video games, working out, career, etc.