YOUTUBE APPEARS TO BE REDUCING VIDEO AND SITE PERFORMANCE FOR AD-BLOCK USERS

Summary from the TLDR newsletter

YouTube appears to be slowing down the site for ad-block users. Turning off ad blockers immediately improves loading performance for affected users. The ad-block detection causes strange issues, like a lag that makes full-screen and comments not work or Chrome being unable to load other webpages while YouTube is open. The slowdowns may be due to ad blockers altering YouTube's code and unrelated to YouTube.