Safari Bookmarks are now listed as end-to-end encrypted on Apple’s iCloud security overview. Previously, only Safari History and iCloud Tabs were. The update was between September 19 and September 25 (presumably with the iOS 15 release).
Via Michael Tsai:
It’s not clear to me when the history became end-to-end encrypted. I’ve heard that this was mentioned at WWDC 2019 for iOS 13 and macOS Catalina. Apple’s iCloud Security Overview also now says iOS 13, but it wasn’t updated to say that until March 2020, long after iOS 13 shipped.
I missed that history and tabs became end-to-end encrypted last year — Apple is not great at communicating these things — but it is long past time all of these things were given the highest privacy protections. Apple treats iCloud syncing of Safari data as an all-or-nothing affair, which has long meant that Apple held unencrypted copies of the complete browsing history of everyone who enabled Safari syncing features, private windows aside. There is no evidence, best I can tell, of any nefarious use or intent, but it is the principle that matters. Safari does a lot to protect users against inherently creepy trackers; it should also, itself, be as secure and private as possible.
And it should have better-designed tabs.