According to my CloudFlare analytics for the last 30 days (I draw on them because they try to measure bots):
2,230,909 Page views
2,094,927 regular traffic
126,337 crawlers/bots
9,645 threats
While there certainly are a lot of automated visits, they are still a fraction of what appears to be legitimate traffic. Furthermore, I'm pretty sure that CloudFlare blocks or challenges (edit: malicious) bot traffic, so I doubt that is the spoon that is stirring the pot.
I am not alone in reporting this: https://www.seroundtable.com/https-google-adsense-19035.html
It is a serious issue, one which I'm sure is hindering https adoption around the web.