What data does the password use retain? IIRC password store retains the "time first used, time last used" and displays that visibly.
In short what's the use-case or user story that fits this feature?
If I have to manually open the correct container first, though, that's a hassle. It's why I use containers sparingly, but hot damn do I have the "facebook container" extension installed (a site I look at maybe once a week) because automatic silos are fantastic.
[0] https://addons.mozilla.org/en-US/android/addon/containers-on...
Say you want to order an engagement ring for your girlfriend but don't want WEDDING RINGS R US showing up when you type "r" in the address bar
Chrome's session and tab management on both desktop and mobile are abysmal. Whilst I've nuked it from desktop, I cannot remove it from Android. And, sadly, Firefox performance there still lags badly.
I browse almost exclusively in incognity on Chrome/Android.
If you use Private Mode all the time then can't you just set the browser to act as if it were in private mode but with more fine-settings choice, that way you could have had password saving all along.
So, I'm still not really seeing the benefit.
That said, presumably the password db could have salted-hashes in in-place of domains/URLs for "privacy mode passwords" and then they'd be very hard to casually discover; that might be closer to user expectations.
Lets compare it to downloads. That's another feature that leaves quite a bit of "compromising" info but users might still want to use it. I am thankful that Firefox does still allow downloads in private mode and did not just disable it. Sure, I could copy all the links into a non private session, but that would be annoying.
Similarly, imagining a situation were saving passwords from private windows might come in handy doesn't seem like a hard stretch to me. It also pretty obviously leaves a trace, just like a download, and thus shouldn't create much user confusion.