That question came up to me, when recently working on one project I needed to restart my PC several times. And therefore, while I used 3-5 web apps I needed to log back in to each one of them again, after each restart. And I started wondering if privacy-wise that auto-clear feature is worth it or not? Has anyone maybe tested that?
I have 3 browsers.
One is my main browser Librewolf, I have a rule when using it: Never sign in anywhere and when I close it all data gets shredded.
Next is ungoogeld Chromium, which I use for shopping and sites where I need to log in. I have some sites cookies whitelisted so they don’t get deleted.
Third is currently Brave for banking. I don’t fo anything else with this browser. In the past I was using Firefox, but one of my credit cards has issues with it and won’t let me download statements.
You may want to start using Tor especially for your current Librewolf use case. Compare fingerprinting
Or mullvad browser to blend in with the crowd