There is an extension called Zoom Text Only in the Chrome browser. This extension allows you to create an individual font size on each page. For example, if you want to set the font size on the Camp Firefox page to 150%, you can do this and the extension remembers this and on a fan fiction page you want to set the font size to 200% because the font size is too small, and the extension remembers this. It would be nice if this were integrated into the on-board tools in Firefox. So far, you can only select a global font size for the entire Internet using the on-board tools. The keyword is individual customizability of a browser. If a browser does not offer individual customizability, people will migrate to other browsers who offer this.