Now I am engaged in optimizing the download speed for mobile devices.
The situation - there is a topic with a lot of YouTube videos. If you look at the topic as a guest, then the speed is normal. For registered users it takes much longer to load.
DOM is built longer.
Extensions that are visible only after entering I turned off - no acceleration. In the browser console in the "network" tab, I did not see anything like that either. By debug, the page loads normally, it is written 0.150-0.220
The question is, what is fundamentally different in the registered and guest versions? I understand that it should be so, and they will not be equal in speed. But how to determine what is loaded and what is not?