From the new terms:
When you upload or input information through Firefox, you hereby grant us a nonexclusive, royalty-free, worldwide license to use that information to help you navigate, experience, and interact with online content as you indicate with your use of Firefox.
Looks like FF is on track for enshittification, I (unfortunately and with great sadness) called it last year (and was downvoted for it lol)
Ladybird is open source by the SerenityOS team but it is pre-alpha so it will be years before it is usable for most people