One thing that shocked me was discovering that Firefox encrypts the saved passwords but doesn't (and won't) encrypt the cookies database at all. https://bugzilla.mozilla.org/show_bug.cgi?id=1259652
> “When contextual suggestions are enabled, Firefox Suggest uses your city location and search keywords to make contextual suggestions from Firefox and our partners, while keeping your privacy in mind,” the support post reads. The “relevant suggestions” from “trusted partners” appear at the bottom of the usual search suggestions pulled from your bookmarks, browser history, and open tabs — a less intrusive version of a search ad, but technically still an ad.
https://www.theverge.com/2021/10/7/22715179/firefox-suggest-...
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I've now switched to Tor Browser - it's a privacy hardened Firefox browser with all the crap removed. (Disabling and removing Tor, which is integrated with it, is a slight pain, but doable).