[kijin]

It only replaces the current page, and VPD is not a single-page app. So if you've been clicking around to find something, the previous pages will still be in your history.

If you need to hide your browsing history from an abusive partner, it would be more secure to use incognito mode and hit Alt+F4 when you need to escape. Unfortunately, Chrome renders incognito windows in dark mode by default. If you're normally on light mode, the transition is extremely conspicuous. Edge and Firefox do the same. It's as if all browser vendors have colluded to make it difficult to browse in secret.

[xp84]

Not enough people know this: in Chrome and Edge, making a Guest window is usually more useful than Incognito. You do it from the profile menu. It’s a throwaway profile, without the various weird special-case behaviors (including the ones websites can detect) that “incognito” has. When you close it, it’s all discarded anyway.

[CM30]

Apparently Firefox has a config option to disable this:

browser.theme.dark-private-windows. Set to false, and you're set.

[kijin]

Thanks for the tip, but the usual open-source "you can change it" argument doesn't work in this case. People who like to control other people will interpret any deviation from the expected behavior as an attempt to hide something from them. If you change the defaults, those defaults can no longer serve as your alibi. All the more reason to ship secure defaults!