AB is riddled with Spyware. It should carry a health warning.
I counted 77 trackers the other day. All that junk loads when you click on a page. It makes AB very slow and often that junk either fails to load properly, or conflicts with another piece of junk which causes page errors.
It is true to say that advertising on free sites is important - however if those adverts cause problems with your use of the site it is little wonder folk either leave a site or use a blocker.
Ads should be quiet,safe and not slow down your normal experience of the site.