This is a common problem among people who work chronically online.
The cognitive load fatigue is a real thing and it hampers your productivity.
I am a victim myself so I can tell you from experience that it leads to proscrastination and productivity loss.
I was in a situation where I would have lost my content writing job if I didn't get my act together because I kept missing my deadlines.
The FocusRead Reader Mode is free forever, the PRO features are always optional and do not interfere with the core functionalities of the extension at all. In short, it never comes between you and your ability to read ad-free online.