I've got #IronFox installed on my phone and have deleted #Firefox ! Again, having never saved passwords or preserved sessions, cookies, etc. made this so easy. I also had already started keeping my bookmarks in a text file on #Fossify Notes (https://www.fossify.org/ or available on #FDroid), so those were no issue either. It's crazy how few note applications for Android allow you to just write notes as plain text files that you can copy to a computer.
I did notice that F-Droid warns the upstream code is not entirely free, and I don't know the specific details of that, but almost anything is better than letting #Mozilla sell my data.