Prolong your browser for as long as necessary and explore the possibility of using the internet without any web browsers. Firefox is a last stand of competition, and without choice there might as well not be browsers at all.
Is it wise to have such a complex everything-app with no end in sight? (more like, no end in site)
When the users are in control of the software running on their devices then “EOL” is dependent the user community’s willingness to work on it themselves.