Sign our petition to stop France from forcing browsers like Mozilla's Firefox to censor websites
(foundation.mozilla.org)
This would make it harder for French users to find an alternative browser, making even more people will stick to the pre-installed Chromium based one.
Sad as it is, I think this is the optimal solution when it goes through. A lot of EU countries are against monopolies (France is not an exception), this way they would realize they are enforcing a monopoly and singular dependency.